One of the most iconic firearms of the Cold War was the diminutive Vzor 1961 (Model 1961) submachine gun made in the Czech city of Uhersky Brod by the firm of Ceska Zbrojovka. More properly classified as a machine pistol than true a SMG, the Vz61 was named the “Skorpion.” This unusual Combloc firearm, of which only a few post-86 dealer samples are currently in the United States, seemed to naturally find its way into the hands of Red Brigade terrorists, Central American assassins and assorted bad guys who opposed American interests.

Skorpion parts kits are available in the US and now, for the first time, a lower receiver made here in the US is available for sale and is specifically designed for direct “drop in” of a Skorpion parts kit. It has just received ATF approval for sale as a receiver which “is not readily convertible” to full automatic. You can now legally possess a Skorpion that is as close to the actual Vz61 as our government will allow without some form of NFA provision.

The Company Behind the Skorpion

RT Manufacturing is the creator behind this US-made Skorpion Vz61 receiver. Co-founded in 1999 in Wauconda, Illinois, by Jack Koziol and a business partner, it was purchased outright by Jack in 2000 and has continued under his management since that time. Employing four full time machinists, it is a general job shop which has several major customers, one of which is a huge entity in the medical precision equipment field.

Jack and his family have been in the machinist trade for many years. After completing a four-year formal apprenticeship program in the machinist field (and winning a VICA “National Machining Championship” in the 1990s), over a 15-year career, he taught himself CAD/CAM designing and its integration with CNC machining. This became key to the Skorpion project.

Aggressively looking for more work in early 2001, he introduced himself to a neighboring firm in Wauconda – Krebs Customs – and started performing subcontractor machine work for them. Krebs is nationally known for quality AK parts and RT Manufacturing began making their muzzle compensators, Picatinny rail fore-end, front sight gas block and other precision AK parts. As Jack had never worked with firearms before, he became increasingly fascinated with their design and manufacture. It was at this point the Skorpion concept emerged.

With RT Manufacturing looking for more projects in the firearms field, Mr. Krebs threw Jack a huge challenge in mid-2003….build a Skorpion lower receiver which can pass ATF muster as a legal semiauto pistol when fitted with a parts kit. Krebs had been very interested in the Vz61 for years but simply did not have the time to properly design and build one themselves given their AK work.

There was only one problem with this. RT Manufacturing had literally no idea what a Vz61 was or looked like. Further, Jack now laughingly admits he did not even know there was a “K” in the Skorpion name instead of the Americanized “C”. For this reason his first Internet searches turned up no information. Not admitting failure, Jack made the October, 2003, pilgrimage to Knob Creek and purchased his first Skorpion parts kit. Though he had the parts kit, he still did not know what it should look like.

Designing the Lower Receiver

Throughout late 2003 and early 2004, Jack carefully examined every piece of the Vz61 parts kit being very interested in how the Czech’s had machined the lower receiver. Fortunately, the kit included the four torch-cut receiver pieces. By examination of their machining marks, he determined their sequence of cuts and the kinds of tools used. He also realized this was not an easy project and why Mr. Krebs had directed it his way.

The Skorpion lower receiver was a true jewel of the machinist’s art. The Czech’s are internationally recognized for their industrial skills and the Vz61 was proof of that reputation. Designed by Miroslav Rybar in 1959 when CNC did not exist and the Communist regime had literally thousands of skilled machinists and many tons of machine tools, the receiver was truly “old school” in both design and execution. During its production run of 1961-1976, the Skorpion was manufactured by manually-controlled equipment. RT Manufacturing could not economically apply this extremely labor-intensive practice to create a new Skorpion. A new receiver could only be profitably cut by CNC.

Jack began reverse-engineering the receiver by using the parts kit itself as the starting point. The overall dimensions of the new receiver were easily captured by the upper receiver from the parts kit. The front of the lower receiver was determined by the takedown pin hole. The rear of the lower receiver was established by the back of the upper receiver where it must snap into place. The magazine well area was defined by the proper lockup of the magazine, while the trigger area was brought into relationship by the rivet hole of the trigger guard. In short, Jack was able to arrive at a fairly accurate starting point for the dimensions of the lower receiver. But that was the starting and not ending point.

Using these initial dimensions, Jack then began using CAD/CAM software to design the first version of the Vz61 receiver. It was a laborious trial and error process in which iterative test cutting was done on blocks of 6061 aluminum. With each passing block the parts kit would fit better. By the 15th block the parts kit simply “dropped in”…with just one problem to overcome.

The front pin hole

Try as he might, Jack could get everything to routinely fit except for the front pin hole. It seemed that one time the parts kit would fit as expected while another would have trouble getting its upper receiver to mount with the front takedown pin and then slide into the rear of the receiver. He even considered making the hole larger to accommodate all possibilities, but, that could lead to a sloppy fit. Finally, by moving the hole a few thousandths of an inch at a time, Jack got it precisely where needed. The temporary loan of a post-86 dealer sample Skorpion ultimately validated the dimensions by allowing direct comparison of the new lower receiver to that of an original. This also facilitated minor cosmetic corrections such as the depth of lightening cuts, etc.

It was now mid-2005 and time to machine a steel Vz61 lower receiver and get it to ATF’s Tech Branch for validation as a legal semiautomatic receiver. Almost two years of work was now coming to this final step.

Manufacturing the Lower Receiver

The receiver is manufactured out of billet 4140 pre-hardened steel. This starts life as a 6.75 lb “hunk of metal” that measures 1.5 x 2.5 x 6.75 inches and is precisely machined down to three-quarters of a pound, an incredible 89% reduction in weight. To achieve this result, RT Manufacturing uses MasterCam CAD/CAM software which is directly connected via RS232 cables to two machines: a Haas VF2 and Hurco vertical machining centers.

While each machine can easily carve a complete Skorpion lower receiver by itself, so much time is consumed to make a receiver that it takes two machines running simultaneously to output a profitable production run. One machine simply could not mill a receiver fast enough.

The MasterCam software produces almost 15,000 lines of G-code to define a Vz61 receiver. In turn, this code controls each machining cut so that every steel billet requires almost five hours of dedicated machine time – and seven separate setups – to be converted into a receiver. Every single internal and external surface on the receiver is touched in some fashion by a carbide cutting tool. Each side of the receiver of this intensive machining takes approximately 45 minutes to make. There are six sides.

After the CNC work is done the lower receiver is still not completed. RT Manufacturing must still perform over 30 minutes per receiver of hand deburring with an air tool to remove all sharp edges. It is then tumbled in ceramic media for another 45 minutes to ensure all internal edges are truly finished. After that….the entire receiver is glass bead blasted to finalize the surface preparation.

Each receiver is then quality checked on a granite surface plate which allows readings to one millionth of an inch. However, for a firearm, this level of tolerance is unnecessary and in fact would lead to an unreliable and far too costly weapon. RT Manufacturing holds the Vz61 receiver production tolerances to +.0025” and for the critical pin holes to +.0005”. These are tighter tolerances than original Czech receivers. But there is still one more “real world” inspection to pass. Will the new receiver accept a Vz61 parts kit? RT Manufacturing verifies this by taking a kit and test fitting the mag well parts into the receiver. A factory mag must correctly lock up with minimal movement. The upper receiver is then slid into place to ensure no lateral deviation and also must smoothly mate with the rear of the lower receiver. Finally, the front takedown pin is snapped into its pin hole and must properly lock up. Upon passing all these inspections the new receiver is stripped and shipped for final finishing.

This final surface finish is a deep black oxide finish that goes well with either blued or powder painted parts kits. The firm which does this is a full time finishing service and has worked with RT Manufacturing for years. Thus, their processing quality and delivery schedule are a known quantity. However, if requested, RT Manufacturing will at no cost leave the receiver in-the-white if the customer wishes to finish it themselves.

ATF Certification of the Lower Receiver

After milling the first receiver in June of 2005, it was sent to ATF’s Tech Branch for examination and validation as a semiauto firearm. This is the single step that has caused more problems and concerns for so many manufacturers. However, Jack’s Vz61 lower receiver passed the first time through in just two months.

ATF issued their approval on 25 August 2005 and confirmed that any receiver which RT Manufacturing made to the specifications contained in that letter would be classified as a semiautomatic firearm. Jack had done his research very well and now had the formal government documentation to validate his work. While the specific internal modifications made to gain ATF approval are proprietary, a copy of the letter will be shipped with each Skorpion lower receiver to assure the end user of a legal firearm. Externally, the RT Manufacturing Vz61 Skorpion receiver appears to be an exact duplicate of the real thing. Side by side, other than the required US manufacturing markings and no folding stock dovetail, you cannot tell the difference.

Building the Skorpion Semiauto Pistol

The absolute first thing to do is obtain a parts kit. Prices have gone higher and availability is getting tight. SILLC of Nevada imported 200 Vz61 kits in the late 1990s and an additional 200 in 2003. These kits were “as new” when decommissioned and first class in all respects. SILLC is importing another group of 130 Vz61 kits but, after that, US government regulations may have shut the door. At a minimum, kits which might come in will not have barrels remaining intact. Yugoslav-made Skorpions, known as the M61(j), are still being produced but their availability is unknown. There are probably less than 550 Czech Vz61 parts kits currently available in the US. So, getting one is the first order of business.

Handling about 20 parts kits over the past six months, it appears that two slightly different variations of Skorpion were imported: One group was made in 1965 and contains all blued parts, while the second type was made in 1975-76 and has a tough, dark grey-blue powder paint finish. Both kits are exactly the same with regard to quality of manufacture and ease of assembly. Each kit comes with a 10-round magazine, lanyard, leather holster and cleaning kit. A special magazine deal is available where you can get two high capacity, factory 20-round mags and leather pouch for about $40.

The Skorpion as delivered from RT Manufacturing arrives in a sturdy cardboard tube and contains the receiver, a slave pin to ease trigger assembly, a trigger axis pin to replace the one in the kit and a small button-head screw which replaces the trigger guard rivet. After cleaning and laying out the parts, the sequence to build the Skorpion is:

1. Bolt hold open, magazine catch and ejector assemblies.
2. Trigger guard, pistol grip screw, rate reducer and bolt stop assemblies.
3. Trigger mechanism and safety selector.
4. Hammer and spring cover assemblies.
5. Bolt assembly and upper receiver.

Construction starts with removing all parts from the kit’s torched central section which contains the bolt hold open, magazine catch and ejector assemblies. Use a 1/16 inch punch and push down on the small detent pin that is at the rear of the ejector. This pin is spring-loaded so once you push it down, carefully slide the ejector forward and remove it; the detent pin and spring are now free to be taken out.

This ejector detent pin also cleverly retains the bolt hold open and magazine catch assemblies. Once this detent pin comes out, these two assemblies will pull out easily. Make sure each of their springs comes with them as these could inadvertently remain hidden inside the torched section due to congealed grease or metal movement from the demil procedure.

Reverse the process to insert them into the new Skorpion receiver. The order should be the bolt hold open, mag catch, and ejector assemblies. To verify all is correct, insert a magazine to ensure it locks up and releases correctly. The Skorpion has a tight well and you will have minimal magazine rocking.

The trigger guard, pistol grip screw/rate reducer and bolt stop assemblies are now installed into the new receiver. The original Skorpion had a riveted trigger guard while the new receiver uses a 4-40 buttonhead screw. Some trigger guards were slightly bent during demilling and thus, depending on yours, it may fit perfectly or require some slight bending/cutting to line the holes up. If the small curved tang on the trigger guard must be removed to obtain proper hole alignment, then do so as it does not affect functioning or looks. You must also enlarge the trigger guard rivet hole with a 1/8 inch drill bit to allow clearance for the screw. Finally, use a drop of blue Loctite and a 1/16 inch allen wrench to install the front of the trigger guard onto the receiver.

Insert the pistol grip screw/rate reducer assembly into the wooden grip, then through the large hole at the rear of the trigger guard. Screw this assembly into the receiver until it seats the wood grip into place. Insert a 1/8 inch punch into the two holes on the bottom cap to further tighten it. You could use blue Loctite but this is not necessary since a wave washer is holding it in place.

Next is the installation of the bolt stop assembly. Insert the “hat shaped” axis pin into its hole in the left side of the receiver and push it all the way through while capturing the rate reducer lever and bolt stop. Make sure the bolt stop has its detent pin assembly in place before doing this otherwise it will not cycle correctly.

The trigger mechanism is relatively easy to complete with a bit of patience. Using a 1/8 inch punch, tap out the original axis pin and remove the full auto controlling lever (aka the “FA sear”) on the right side of the assembly and bolt hold open connecting lever on the left side. Discard the FA controlling lever as it will no longer be used on this semiauto pistol; however, set aside the bolt hold open connecting lever as it will be reutilized. Next, insert the provided slave pin through the axis hole on the right side of the receiver, then through/capturing the remaining parts of the trigger mechanism, and into its corresponding hole on the left side, to temporarily fix it into place.

Now, slightly withdraw the slave pin back towards the right and drop the connecting lever back into place on the left side of the assembly. The forward tip of this lever must fit into the hole on the back of the bolt hold open button. Line everything up and tap the new axis pin into place from left to right. This will push out the slave pin while keeping all parts aligned. The single groove on this new axis pin must be on the left so the connecting lever can snap into it. Once again, the single groove on this new trigger pin must be on the left side.

Now, take the safety selector and insert it into position from left to right and rotate counterclockwise into place. You will have to depress the bolt hold open button to mechanically lower the connecting lever in order to give the safety selector enough entry clearance. To validate its proper installation, flip it back and forth from “0” to “1” several times. When installed properly you will see the bolt hold open go up and down.

The hammer assembly is installed by inserting the main spring into the main spring guide. This guide is the cylindrical housing attached to the front of the trigger assembly. Then, insert the main spring strut into the spring and slide the entire hammer assembly down into the receiver. Insert the flathead axis pin from right to left and you are complete. The hammer stop pin is then inserted through the receiver from left to right. Finally, drop the large and small detent pin assemblies into their holes on the bottom of the receiver and slide the spring cover over them. Make sure the pins fully snap into their respective holes in the cover.

To attach the upper receiver you use a small needle or dental pick to push in the tiny detent pin which is found on its left mounting arm. Push it in just enough so you can rotate the takedown pin and force the detent further back into its hole. Then, withdraw the takedown pin just enough (about 1/8 inch) to allow the upper receiver to be installed onto the mounting lug of the lower receiver. Push the takedown pin into this lug and then rotate it until the detent snaps back into position. The upper receiver is now locked onto the lower receiver.

Insert the complete bolt assembly into the upper receiver, drop into place the two cocking knobs and then slide it all the way forward. Swing the upper receiver down onto the lower receiver, push it back 1/4 inch until it stops, then snap the takedown pin all the way home. Congratulations, you have just built your Skorpion pistol.

Obtaining the Skorpion Lower Receiver

RT Manufacturing has invested many man-hours of time and research into this ATF-approved semiauto Skorpion receiver. It is the first one of this quality, and the first ever, to come onto the US market. With five hours of CNC machine time per receiver, an additional two hours for hand deburring, inspection, test fitting, tumbling, plus the black oxide finish, it is a high quality product.

The current retail price from RT Manufacturing is $645 and includes insurance and delivery to anywhere in the United States. Volume purchasers will receive pricing discounts and should contact Jack for more specifics. Add to this the cost of an original Czech Vz61 parts set and for less than $1,000 you have an iconoclast of the Cold War which will truly enhance a small arms collection. More than that, it is just pure fun to shoot with widely available ammunition.

Mods and Sods

The .32 ACP ammo that the Skorpion fires is a light recoiling cartridge. More importantly, the common 71-grain FMJ projectile is easily subsonic at approximately 900fps. This means the Skorpion is an excellent candidate for suppression. But, there are currently no suppressors being built in .32 ACP by the leading manufacturers such as Gemtech, SWR, etc.

RT Manufacturing is addressing this gap by optionally installing an H&K-style three-lug adapter to the muzzle of the Skorpion barrel and allowing a standard 9mm snap-on suppressor to be mounted. Though the 9mm aperture is inefficiently large for a slug measuring 7.65mm in diameter, it is dealing with substantially less expanding gas and the sound signature remains very quiet. Thus, for those owners who already have a 9mm suppressor of this type, there is now an additional weapon which can use it. RT Manufacturing will sell/install the adapter for a nominal charge and this option should really be looked into by the enthusiast.

Another option being investigated is a .22 conversion kit. While still in the initial planning stage, this possibility could greatly reduce the cost of firing the Skorpion. Since the factory barrel is pressed and then pinned into a steel trunnion, some form of .22 barrel liner is being looked at as a viable solution. Of course, the issues of magazine modifications, bolt, offset firing pin, spring rates, etc. must all be dealt with. This option is clearly further down the line but not outside the capabilities of the firm.

Finally, for those who possess the proper NFA authorization, RT Manufacturing will sell a fully automatic version of the Skorpion as a post-86 Dealer Sample firearm. This has already been tested and works as reliably as the original Skorpion. In fact, of the first production run of 50 Skorpion lower receivers, 15 of these are already spoken for as post-86 versions. As before, contact Jack for additional information on this option.

Conclusion

Rare, unusual, hard to “quite-really-define” what category it fits into, the Czech Vz61 Skorpion has been an enigmatic firearm since its shadowy introduction over 45 years ago. Ostensibly designed for armored vehicle crewman who needed a small and efficient firearm in their cramped quarters, it typically found its way into terrorist, police, insurgency and other paramilitary hands. Other than a handful imported into America, this situation has been clearly remedied by RT Manufacturing.

Their ATF-approved semiautomatic Skorpion lower receiver is a superbly designed piece of the machinist art. Externally it is an exact duplicate of the original version and is cleverly built to accept the drop-in of a Vz61 parts kit. Made of proper 4140 pre-hardened steel and cut on modern CNC milling machines to the highest tolerances, it is a delight to own and fire. RT Manufacturing has certainly done their homework on bringing this Skorpion to America.

Sources

RT Manufacturing Company Inc.
Attn: Jack Koziol
1000 Rand Road, Unit #212
Wauconda, IL 60084
(847) 487-7562
SILLC
631 N. Stephanie Street, #372
Henderson, NV 89014
(702) 564-0521
surplusllc@aol.com
www.sillc.com

By William R. Bishop

Perhaps the single most visible factor when evaluating a legally converted HK full auto firearm is the manner in which it is refinished. Does it have that smooth satin black finish like that of an Oberndorf-produced firearm? Or, much more likely, does it have a grainy black finish which came out of a spray can from the proverbial hardware store? Does this finish obscure small proof marks, become easily abraded, not fully resist all firearms-related chemicals, and have the color shade and sheen which screams “cheap”? Heck, if this is the situation – and it is in so many cases – then are the conversion and associated machine work also of low quality? What else could be wrong with it?

If your HK finish is in this undesired category and you have been searching for a economical way to closely replicate the superb finish from Oberndorf there is now salvation. Coat it via the same electrostatic process the Germans use!

The rest of this article will describe in detail a new product which has recently come on the market and how it is used to duplicate the legendary HK finish. SAR will take you through the entire process as it is applied to an HK 94 semiauto carbine during its conversion to a MP5A2. The end result would make Oberndorf proud and….well…you be the judge of this!

Theory of Operation

Electrostatic spraying is a very straightforward process which HK has used for years on its longarms. An extremely fine grained coating is sprayed from an electrically charged dispenser onto a grounded piece of metal, which then attracts and holds the coating onto its surfaces. It is very similar to static electricity (hence the common name of “electrostatic spraying”) attracting dust to a glass rod. The coated metal is then transferred to an oven and baked for a specific period of time, causing the coating to tightly fuse to the surface. During this curing process the coating becomes self leveling and extremely durable. Also, there is no hazardous waste, little overspray and highly efficient use of the coating material. It is very environmentally friendly.

There are two types of coatings which are typically used in this electrostatic process: 1) liquid coatings which are sprayed at 35-50psi and require up to 80KV DC to charge the particles; and, 2) powder coatings which are sprayed at 5-10psi and a 9KV DC rate. The functional difference (hardness, bond, appearance, etc.) between the two coating methods is quite small. The main difference is cost, as the liquid method outfits go from $4000-7000 and require stronger electrical current, higher rated compressors and fairly specialized equipment. The powder method requires significantly less of everything, but, when compared to the liquid method has a fairly limited range of color availability.

HK uses a two-part epoxy liquid finish for its electrostatic painting. This method yields a beautiful coating which is recognized around the world. But, it requires very expensive equipment which is beyond the range of practically all individuals and most shops in the United States. The alternative to this – the powder method – has not been available at a cost effective level…until now.

Another name for this powder method of electrostatic painting is “powder coating” and this process has finally become available for our use at home. Most importantly, a color is now available we sure can use and at a cost we can afford. In short, we can now almost duplicate the HK finishing process by using the much lower cost powder coating method of electrostatic spraying!

The Powder Coating Kit

The Eastwood Company of Malvern, PA is very well known in automotive circles for their unique line of products in the areas of restoration and repair. As a member of an automotive club, I had heard about this revolutionary product which was the answer to many restorer’s demands. I was also in the process of converting my HK94 carbine to full MP5A2 specs and had long dreamed of finishing via the HK factory process. Could the Eastwood kit be the answer to my prayers? A phone call to Eastwood had their “Hot Coat” powder coating outfit on the way to me.

What arrived was a well designed unit which looked sort of funky, but, the very complete instructions (read them first!!!) began to dispel my concerns. I had already received from them several paint chips to determine which one was closest to HK satin black. Fortunately, their #10103 powder proved to be an almost exact color match to the factory finish of a late production MP5.

After reading the instructions several times – I was not about to mess up my expensive HK 94 or get zapped by 110v house current – it was time to go. But first, an overview about the conversion process to MP5 specifications, as several C2’s out there really deserve some recognition for the skills and service they provided.

The Conversion

I had a S&H Arms of OK registered sear already installed in a HK94 trigger pack and wanted my HK94 carbine converted to as-near-to-factory specifications as possible. The first step in my conversion process was to get it remarked. Ron Moyer of Class Three Supply told me they owned a $5,000 New Hermes engraving machine with a 7-way fully adjustable bed. The key words were “fully adjustable bed” as it could positively retain the HK94 at any required angle throughout the engraving process. Further, Ron guaranteed the MIG welding of the existing HK94 script, surface milling the receiver flat, and remarking with “HK MP5” would be to precise Oberndorf standard. Well now! After viewing many remarked MP5’s which ranged from crudely hand stamped to near-perfect engraving, this seemed to be a bold statement.

But…Ron was 100% good on his word with the final marking of “HK MP5” even neater than HK could do! Clearly, Class Three Supply has set the standard for welding/remarking the HK 91/93/94 series of weapons.

Now it was time to gather up the conversion parts. Considering the market value of a fully transferable MP5, I deliberately chose to use all German parts for my conversion. The cost would be high, but the increase in value would offset it. Once again, Class Three Supply came to the rescue with an SEF plastic lower, front sling pin, true MP5 (not G3) paddle mag release, and spare locking pin for use as a fake push pin. Emails to “Jack at Public Safety” yielded a German MP5 bolt carrier while “Bob T.” produced a new-take-off German MP5 8.85” lugged barrel. Time for the actual conversion to be done.

I had heard many good reports on the work which Joe Gaddini of SWR was doing and gave him a call about my project. We agreed he would perform the barrel replacement/headspacing, milling the SEF plastic lower to fit the semiauto HK94 receiver, installation of the pseudo SEF locking pin, installation of the MP5 paddle mag release, and bead blast/parkerize the entire receiver. He would then ship it back to me for the final powder coating and reassembly.

Everything was collected and forwarded to Joe for his use…and…Joe did a 100% superb job to absolute factory standard. There was not one slight thing which was out of place or incorrect. Turnaround time was one month – this alone is darn near a miracle – while his costs were very competitive.

The barrel was pressed into place/headspaced at the optimum .015” and the lug pointed exactly towards 12 o’clock; the new sling pin was straight and its head was flared to standard. The cocking tube was precisely centered into the front sight assembly and the SEF plastic lower was carefully milled out to firmly fit onto the receiver. Its fake push pin was neatly sliced and epoxied into place. As requested, the head of the pin was on the left and the spring tip was on the right so it matches the two real locking pins The paddle mag release was installed into its blind drilled hole and then the insertion hole was filled with stainless steel. Joe then stoned this area to be exactly flush with the receiver. Finally, the bead blasting and parkerizing was completed and to the same color as a German factory MP5.

In my opinion, having seen numerous HK conversions, Joe Gaddini’s MP5 work exceeded my strictest demands and rises to the level of artwork. It is that good. Powder coating time!

Description of the Hot Coat System

The Hot Coat powder coating system is well built of plastic and metal. It is comprised of the paint gun itself and a 120V DC power unit. This unit has three cables: 1) one running from the power unit to the gun and supplying 9KV DC; 2) one to the target part and acting as the ground clip; and, 3) one to the push button activation switch. Finally, a can of #10107 high gloss black powder paint is included with the kit. If you talk with Eastwood be sure to ask if they can substitute a can of satin black #10103 for the semi-gloss black. But, as extra powder paint is only $10 per can, it is just as well to order the satin black separately and give yourself a wider color range.

A very well written and complete booklet of instructions comes with the Hot Coat system. The main thought behind the instructions is quite simple: this is a straightforward process to do, but it must be done safely. You will be dealing with 110V house current which is normally not deadly, but can give a nasty shock. (Editor’s note: 110v current can easily kill you if it grounds out through your body passing vital organs-Dan) Also, the paint is a very finely ground polyester powder and as such can be explosive if allowed to build up into too great an aerial concentration…sort of like the old “dust bomb” we learned to make at Special Forces school. For this reason, no flames or spark should be in the area of painting. Pilot lights from hot water heaters, extraneous sparks, cigarettes, etc. are to be avoided. This means the oven performing the thermal curing must be electric and not gas. Finally, the instructions specifically state this oven should not be used for food service. More on this later!

A few extra supplies you should get from Eastwood will include some of their special Hot Coat moisture filters, high temperature silicone plugs and fiberglass masking tape. Total cost for all this is less than $225 for a kit that will last for years. Plus, the tape and plugs can be used for other related gunsmithing services (molycoating, parkerizing, etc.) and further reduce costs.

Preparation for Powder Coating

The absolute surest guarantee of a first class powder coating job is surface preparation. It is that simple. My MP5 had all removable parts including the front sight blade, rear sight assembly, cocking handle/support, front end cap and most of the mag well locking assembly stripped from the receiver. The only parts which could not be removed were the flapper mag lever itself and its 1/8” stainless steel axis pin. These were permanently installed and would require masking.

After stripping the receiver, it took almost two hours to thoroughly degrease it. This very critical process was accomplished by painting it with acetone via an acid brush, letting the solvent evaporate, and then warming it in an oven for 10 minutes at 150F. This caused the remaining oil to creep out of the metal’s pores and internal crevices. After 6-8 trips from the oven, to degreasing, and then back to the oven, all oil had flowed out and left behind a totally bone dry receiver. Particular attention was paid to the rear sight flat, front sight/barrel mount point and especially the barrel trunnion areas. This trunnion area was very time consuming to degrease as the heat seemed to bring out a never-ending supply of oil trapped between itself and the receiver shell. But, this tedious process must be done to achieve a properly prepared surface.

As the painted receiver would be thermally cured at 400F for 15 minutes, the traditional masks of newspaper and tape would not apply. The temperature would be too near their ignition point (paper burns at 454F according to Ray Bradbury) to take any chances of combustion. To eliminate this worry I used Eastwood’s previously mentioned fiberglass masking tape and high temperature silicone plugs. Also, standard aluminum foil is used instead of newspaper to fill up the larger cavities and protect them from errant overspray.

Start the masking process by putting on a pair of vinyl or nitrile gloves so that no skin oils can accidentally get onto the prepared surface. Next, insert a 1/4” unfinished wood dowel rod through the muzzle and all the way out the other end of the receiver. Cut it off so that about 4” sticks out from both sides as this will be the primary means of handling the receiver and suspending it in the oven. Carefully tape off that portion of the lugged barrel which will not be painted. When doing so, continue the taping so that it secures in place the dowel rod extending from the muzzle. We do not want the rod to slip and that precious receiver to drop!

Now, use a combination of aluminum foil and fiberglass tape to mask off the rest of the receiver. Pay particular attention to the mag well area and very carefully mask the mag release lever . Factory MP5’s have about .25” overspray into the well and absolutely none on the lever itself. The rear of the receiver is sealed off and no more than .10” of overspray should intrude. The bottom of the receiver where the SEF plastic lower fits should allow only about .10” overspray. The only other part to coat is the front end cap, which is easily taped off so the visible front portion is left exposed. Take your time and figure that about an hour will be required to do it all correctly.

Now, the final step before the actual painting is to take some unfinished stove wire, or Eastwood’s stainless steel safety wire, and rig it to both ends of the dowel sticking out of the receiver so it can be suspended from the top rack of the electric oven. Run another piece of wire through the tape that is masking the front end cap. Do a test hang to verify the receiver and cap will touch nothing during the upcoming thermal curing and also to give them one last warming/acetone degreasing. By now, there should not be any evidence of oil seeping out! When you pull them out of the oven for the last time before powder coating, turn the thermostat up to 400F so it can heat up while you are painting.

Powder Coating

The paint gun is first adjusted to achieve the correct pressure before any painting is ever done. My 3.5HP Sanborn 115V compressor has both a pressure regulator and Campbell Hausfeld water trap installed, plus, I used the optional moisture filter which Eastwood has available for the Hot Coat gun. A third water trap consisting of a Norgren trap/pressure regulator was directly attached to the sprayer. The air must be dry when dealing with such fine powder! Adjust the pressure so that no more than 10psi is coming out. 8psi is the optimum pressure as you want a wafting of powder to come out and form a charged fog around the target part. Too much pressure will simply blow the powder past the part and also blow off any powder which did hit the part. Once again, you want a fog – and low pressure is the answer. The minimum pressure which the gun can correctly use is .5cfm at 5-10psi…pretty low pressure!

Once the pressure is adjusted to 8-10psi, take the powder and carefully pour it from the can into the cup, using a cone of glossy paper, to a level of 1-2” deep. Do a test spray into the air to make sure the pressure delivers a fog and not a hard spray. Adjust the regulator as necessary to achieve the fog.

Now, suspend the masked/degreased receiver and end cap from an overhead support. I used 550 paracord as it is strong, cheap and available. Any support such as a broomstick, dowel rod, 2×4 lumber, etc. is OK. With the Hot Coat power unit plugged into a grounded 110V outlet, attach the ground clip to the receiver. I attached mine to the underside of the rear locking pin bushing.

Let’s see…the pressure is tested and powder fogs out…the power unit is plugged in…the receiver is grounded…let’s go.

Press the button on the activation switch and a second later squeeze the trigger on the paint gun. Air pressure flows through the gun and mixes with the powder in the cup. The fluidized powder flows up from the cup and down the emitter tube where it receives a positive charge. When the paint exits the end of the gun it forms a black fog immediately to the front. At the same time, the clip attached to the receiver has caused it to become grounded so the fog is gently sucked down onto the negatively charged metal. It is truly amazing to watch how this fog seems to blow out of the gun and then slowly change its direction to attach itself to the part.

Be sure to direct your immediate attention to the various nooks and crannies on the receiver, such as the rail areas, so they get painted first. This helps avoid a too thick buildup of the powder in adjacent areas by the end of the job. Paint in a circular pattern and coat everything evenly from several different angles. Typically, the distance from the emitter to the part is about 6” – pretty close, so do not accidentally touch the emitter to the part. After a minute, release the activation button and carefully inspect the receiver for powder thickness. If it settles too much in one area, simply tap the part with a wooden implement so that any loose powder shakes down to a lesser coated area. Over the next few minutes continue this process of painting the receiver, stopping to inspect, shake/tap if necessary, and proceed with more powder. After about five minutes you will be completed when the receiver is evenly coated with a matte covering. Release the activation button, unhook the receiver’s ground clip and give that exposed area one last fog of powder to coat it.

Attach the power clip to the front end cap and proceed with the same process. It goes very fast and is done in less than 15 seconds. When finished, release the activation button and remove the ground clip; give the exposed area a final fog. Unplug the power unit, discharge the emitter tip to the ground clip, put down the gun and you are finished powder coating your almost-completed MP5.

Thermal Curing

Carefully pick up the receiver/end cap and take them to the electric oven, ensuring to not bump anything or allow wind flow to disturb the charged powder. Hang them via the support wires from the top rack and close the door. As the oven should have already been preheated to 400F all there is to do is wait for magic to happen. Watch through the viewing glass until the powder on the parts has “flowed out” and the entire surface of both parts has a shiny wet appearance. As it is significantly smaller, the end cap will flow out first and then the receiver. For me, flow out occurred at the one minute point. Now, turn on an accurate timer for precisely 15 more minutes.

At the end of 15 minutes immediately turn off the heat, open the door and let everything naturally cool down. Do not breathe the fumes which come roiling out!!! Let the temperature stabilize over the next 10 minutes while inspecting them for any thin spots or imperfections. If there are – there probably will not be – then simply respray and repeat the process. Final thought on the oven: if you cheated and used a food service electric or toaster oven (some of you will), thoroughly clean it and ventilate the house before the wife returns. The gaseous fumes (isocyanide, I believe) given off by the curing will gag a maggot. Walter T. Birdsong of “Black T” fame very seriously advised to get an old oven and use it in the garage as the curing fumes can embed themselves into the wall of the oven. This is excellent advice from an industry leader in firearms refinishing. I now have two used ovens sitting in my shop for future use. The following warnings are located in the instruction manual and should be followed:

“Always cure powder in a well-ventilated area and wear an activated charcoal respirator while curing to protect against unpleasant fumes. Once the curing is complete, allow the part to cool down gradually by turning the oven off and opening the door slightly.”

Page 12, the Eastwood Company “Hotcoat” Instruction Booklet, Rev 5/99

“Do not use an oven used for food preparation or located in a living area, as mildly toxic fumes are given off by the powder residue during the curing process! Do not use a gas oven!”

Page 4, the Eastwood Company “Hotcoat” Instruction Booklet, Rev 5/99

After the parts have completed cooling, remove all the masking and be amazed at the results. Carefully oil/reassemble everything and you now are the proud owner of a MP5 which equals the beauty of HK/Oberndorf’s output. Truly, a factory-correct finish which gleams like a satin black jewel.

Conclusion

The Hot Coat powder coating outfit from Eastwood is a quality product which delivers a first class finish and is well within the budget of practically all home hobbyists. By following the detailed instructions and properly preparing the target surface it delivers a coating which closely replicates that produced by HK Oberndorf. As shown in this article, when the Hot Coat system is applied over an HK94 receiver – which has been converted by professionals such as Class Three Supply and SWR – you are assured of a highest quality weapon which yields increased market value…and years of first rate service.

Where to now? Well, the #10103 satin black powder is perfect for refinishing so many of our most popular C3 items out there. The IMI Uzi, FN FAL, Belgian FAL and FNC magazines, 9mm/.22RF suppressor tubes, etc. immediately come to mind as excellent candidates. You are only limited by the size of the electric oven, ensuring the parts can be electrically charged and tolerate 400F heat, and your imagination. And SAR readers are noted for having large imaginations!

The Eastwood Company
Box 296
Malvern, PA 19355-0296
(800) 345-1178

Class Three Supply
Attn: Ron Moyer
1400 N. Hermitage Road
PO Box 1119
Hermitage, PA 16148
(724) 962-1890

SWR
Attn: Joe Gaddini
119 Davis Road
Suite G-1
Martinez, GA 30907
(706) 869-0026

In the first part of this two-part series on Fabrique Nationale’s FNC carbine we learned about its background, technical details and operating characteristics. Now, in this concluding episode we will go into the details of actually converting an FNC into a thoroughly reliable select fire weapon. This is done using a registered transferable sear. Yes – it can be done – and to factory standard, too!

When you consider a weapon for conversion to full automatic (fully transferable, of course) there are four critical areas to research:

* Design of the base weapon itself. Does it lend itself to conversion with few additional changes?
* Are appropriate feed devices such as high capacity magazines available in sufficient quantity?
* Is it in an available ammunition caliber? Preferably, it should be procurable in milspec surplus lots which are made on modern equipment with quality components.
* Finally, and foremost, is the BATF-registered part (sear or bolt) actually available and at a price that will not make you take a second mortgage on the house?

The FNC is an excellent candidate for transformation into a true assault rifle. It is well built with a solid design. When FN manufactured approximately 6000 semiautomatic rifles for import into the US during 1982-1988 they made few changes from the standard military version. For conversion purposes, this means intricate machining and/or parts replacement will not be necessary. Unlike conversions such as IMI’s Uzi which had numerous deviations from the full auto design (barrel trunnion, receiver bolt block, sear holes, safety block, etc.) the imported FNC remains very close to the original. This was taken to such a degree that semiauto FNC’s retained the built-in rifle grenade sight which, when activated, cuts off the porting through the gas block. Even the owner’s manual is the same as provided to military users.

Other critical areas which indicate the FNC is a superb candidate for select fire conversion include the type of high capacity magazine it employs and availability of milspec ammunition. As the mag well is built to NATO STANAG 4179 and uses milspec 20 and 30-round M16 magazines the reserve of highcaps is essentially limitless. Further, the supply of milspec 5.56mm ammo which duplicates the performance of the US M193 55gr. round is quite robust and will be for years into the future. Should you handload, the components such as powder, brass and bullet are all available in bulk lots.

Finally, the last and most important question regarding a fully transferable conversion to full auto: what does BATF consider to be the registered part and are any available? This is not an idle question given that H&K sears sell at $2500, AR15 auto sears around $2300 and Uzi 9mm bolts at $1300. Even with these stratospheric prices there remain very few available on the open market. The demand far outstrips the supply – and it will only get worse.

I knew from my research the FNC passed the first three checkpoints with no problem. Its semiauto design is extremely close to the military version and it fires the 5.56mm M193 cartridge via common AR15 magazines. So far so good. Now, what about the registered part? What was the availability and cost of this critical item?

Good news!

BATF considers the registered part to be the trip sear and…and…it is plentiful and available at a very reasonable cost!

Amazingly, the cost of this sear and the entire process to convert the FNC to select fire can be done to the highest standards and for as low as $800. Should you wish to convert your FNC to select fire with a three-round burst option the cost modestly increases to $1000. Now that you have recovered your breath and demand to know more, let’s see how this modern-day miracle is really performed.

Conversion Process

The conversion of the FNC to full auto follows the same basic process as used in AK and FAL conversions. This process includes:

* Lower receiver modifications
* Bolt carrier modification
* Function testing

While there are numerous nationally known C2 manufacturers who can properly convert various weapons to select fire, only one can do it for the FNC. This is Curtis Higgins of S&H Arms of OK. The remainder of this article will focus on Curtis’ work as he has consented to allow Small Arms Review into his shop and see how it is properly done.

Curtis is nationally known in the C2/3 business and has been in operation for many years. He has offered a select fire version of the FNC since 1986 which is classified by BATF as a registered sear gun. What makes Curtis’ conversion so desirable is that he uses an absolute top quality sear and and now has access to brand new factory full auto fire control parts. This conversion is then carried out with very high precision metalworking equipment and finished with a correct selector switch remarking. The end product is as close to a genuine factory FNC as you can get this side of Liege, Belgium.

Let’s now follow Curtis as he converts a semiauto FNC into a true select fire rifle. The end result will be a most interesting weapon with a very appreciative market value – and really fun to shoot!

Lower Receiver Modifications

The first thing Curtis does when he receives a customer’s FNC is to thoroughly inspect it for wear and serviceability. Any part not meeting factory specifications is noted and the customer is contacted for resolution. Due to the FNC’s reliability and escalating market value he has never received one in unserviceable condition. Further, Curtis makes very sure all parts are bagged and kept together with the same rifle. What you send him is what you get back – nothing is “swapped” out.

Next, the lower receiver is partially stripped in preparation for installation of the registered sear and selector remarking. The first thing to be pulled is the fire control mechanism. This is done by rotating the selector switch to the 12 o’clock position and extracting it to the left. Levering out the safety support cradle and its axis pin allows removal of the fire control mechanism. The hammer spring and spur are then rotated out with the use of a special tool. This tool captures the head of the spur and allows spring compression and outward rotation. Next, the hammer axis pin, SA hammer, trigger pin, trigger and trigger spring are all removed. Then, the magazine catch pin is drifted out and the catch along with its spring are withdrawn. Finally, the handgrip and buttstock have their retaining screws removed and these items are pulled off.

With the lower receiver mostly stripped – essentially the two receiver pins are all that is left – Curtis now engraves additional selector switch markings to reflect its full auto status. The markings on a semi FNC are “S-1” to show safe and semiauto functioning. The additional markings of “3-A” are then added to identify the three-burst and full auto functions. He does this by first bolting the stripped receiver onto the bed of a carbide-tipped rotary engraving machine. Positioning must be very precise as no mistakes are allowed. Once the receiver is engraved, you cannot go back and re-do it again!

After verifying with a machinist’s rule the final location of the “3-A” symbols, Curtis places the pantograph stylus into the copper scribing template and begins the cuts. After several minutes of constant work, and a final wiping away of the cutting oil, the new “3-A” symbols are revealed. He then fills in these symbols with red enamel to match the existing FN markings. The result is a four-position lower receiver (S-1-3-A) which is factory correct in function and appearance. It is simply beautiful.

With the fire control mechanism removed and the selector switch symbols added, it is time for the sear installation. The process in doing so is proprietary to S&H Arms of OK, but having observed it first hand I can assure you it is absolutely reliable and simple. Total time to install one is approximately twenty minutes and once in place is a very rugged addition to the FNC. The sear itself has a Rockwell hardness in the mid-40’s and is made of 4130 steel which has been precisely machined and hardened via an oil quenching. Its shape, location and the relationship it presents to the hammer and bolt carrier were all developed by Curtis. Further, he has never had a sear fail or wear out.

After the sear installation is completed, Curtis performs final quality checks and then begins the fire control mechanism upgrade. There are two routes he may now take: 1) safe-semi-full auto functioning, or, 2) safe-semi-burst-full auto functioning. The choice is up to the customer. The initial entry route of $800 will get you choice 1, while an additional $200 will gain you choice 2. Guys, spend the additional funds and get choice 2 as it is what makes an FNC truly factory correct!

For choice 1, Curtis notches the existing SA hammer and installs all the original fire control parts back into the FNC. A note of interest: unlike semiauto Colt AR15’s, the semiauto FNC selector switch is exactly what the military uses and already machined to support both full automatic and burst fire. One less replacement part to worry about! The conversion is now complete and when the selector switch is placed in the “burst/3” mode will continue to fire semiautomatic.

Choice 2 is much more interesting. First, he deletes the semiauto hammer and its safety support cradle and replaces them with a factory three-shot burst ratchet counter and full auto hammer. These rare parts are produced by the FN-licensed factory in Indonesia and are fully equivalent in specification to those from the European FN plant. Once unheard of in the US, these items along with a complete line of brand new FNC parts are now being stocked by Tampa Bay Military and Police Supply. If you own an FNC you need to call them.

With the necessary fire control parts replaced, the lower receiver work is completed by installing the trigger, mag catch mechanism, furniture, etc. Final quality checks are then performed by Curtis and the lower receiver conversion is now complete.

Bolt Carrier Modification

The bottom of the bolt carrier is modified by building up a sear trip shelf with TIG welding material. It is then carefully machined to correct (and proprietary) dimensions with a Bridgeport mill. This is a critical step as the timing of the full automatic process is dependent on the precise moment when the modified bolt carrier trips the registered auto sear. The sear then releases the hammer after the bolt has achieved lockup with the barrel extension. Incorrect timing of the bolt carrier could result in poor functioning, a destroyed receiver – or worse.

Sequence of Operation

When the selector switch is placed into the full automatic (“A”) position and the trigger is pulled several things start to happen. The hammer, which has been held back by both the automatic safety and secondary sears, is set free. It rotates forward and strikes the firing pin, which then impacts the primer to begin the ignition sequence. When the hot gasses from the burning propellant pass the barrel porting hole some of them are bled off to travel through the gas block. These gasses impinge on the gas piston and drive back the bolt carrier assembly. During this rearward travel a ramp on the bottom of the bolt carrier strikes the hammer to rotate it backwards. Since the FNC is in the “A” position a cut in the selector switch axle has caused the secondary sear to be rotated back and out of position. The hammer is therefore not caught by this secondary sear and is retained by just the automatic safety sear. As the bolt assembly moves forward it strips off a cartridge, which is then pushed up the feed ramp and into the barrel chamber. When the lugs on the bolt begin to lock into their recesses the bolt carrier trip shelf impacts the automatic safety sear. This sear then disengages from the hammer which in turns rotates forward to strike the firing pin…and the sequence begins again. Whew! And to think this occurs approximately 700 times per minute.

When the selector switch is in the “3” position a slightly different sequence occurs. Each time the hammer rotates forward it contacts a spring-loaded pawl which is part of the three-shot burst mechanism. The rear tip of this burst mechanism engages the secondary sear and keeps it off the hammer. When three rounds have been fired and the pawl has clicked its way through the toothed counter, a spring flips up the burst mechanism which then releases the secondary sear. This sear re-engages the hammer and holds it back. Should the trigger be released before three shots are fired the spring-loaded burst mechanism snaps back to reset itself in preparation for the next burst. Typically, a three round burst can be fired in .2 second.

When the selector is in the “1” position the secondary sear is always engaged to hold back the hammer after each shot.

Function Testing

The final part of the conversion is a live fire test. Curtis runs a magazine of either Olin or Federal “white box” paramilitary ammo through the FNC to check semi, burst (if ordered), full auto and safety functions. As the rounds are going downrange he carefully observes the timing, ejection pattern, ignition reliability and intangibles. Once the FNC passes this real world test it is carefully packaged back up and shipped to the customer upon ATF form approval. Curtis is adamant that nothing is shipped until he talks with the actual person receiving the FNC.

FNC users have reported to me the full auto FNC is sometimes partial to certain brands of ammo. While all brands function quite fine in the semi mode, Winchester and Hirtenberger rounds sometimes cause stoppages in burst and full automatic. The suspected problem area is the pressure curve generated by their powder. South African, IMI, PMC and other 5.56mm rounds work fine in any mode. Also, commercial reloaded ammo seems to work very well regardless of selector switch setting.

Shooting Impressions

Firing the FNC on full auto is very similar to that of the M16-series rifle. Recoil seems to be a little more robust due to a different buffer system which has less spring length. This may also accentuated by the very solid folding stock which transmits the recoil into the shoulder. Also, the lack of a bolt-hold open on the last shot requires a bit of getting used to as the Europeans do not view this as being necessary on a small arm. Further, given its barrel diameter/length and cooling efficiency the cyclic and maximum rate of fire should be the same as the M16A1 – 700 and 65 rounds per minute respectively. This is typical for a modern, small caliber, select fire assault rifle.

Since the cost of full auto weapons is continuing to go through the roof, the wear endured by the FNC when wringing it out should be considered. This is an area where it shines, and for several very good reasons! The barrel itself is hammer forged and then chrome lined. This results in a hard barrel with a “slippery” bore which is resistant to excess wear. Should you have someone cyrogenically freeze the barrel to eliminate internal stresses and increase its surface hardness the wear will be reduced even further.

The barrel extension (which contains the locking lug cutouts) and twin-lug bolt are cast and then machined. The bearing surfaces in these two areas have a very large amount of contact and thus further reduce the wear as impact/shear forces are spread over a sizable area. My experience with Swedish FNC’s (known as the AK5) in Bosnia indicates that wear of the barrel and bolt assembly are not an issue. Even so, TBMP is importing high quality factory parts to provide backup. Purchase two spare firing pins and perhaps one additional hammer spring to gain peace of mind.

When the FNC is fired the brass does get dented a bit. The case mouth bounces off the right side of the receiver and cocking slot cover before pitching to the side. Typically, a smoking pile of brass will build up 20-30’ to the right front of the muzzle. As the FNC can rapidly eat ammunition I save handloading time and use the excellent quality 55gr. IMI M193 cartridge which is available from Cole Distributing. Recent accuracy testing I conducted on this round (with my FNC) clearly showed it yielded 2-2.5 MOA even after extended fire – with iron sights! Finally, that nice black enamel finish on the barrel does have one weak point. After a short period of firing the area of the barrel just in front of the chamber will exhibit scorched paint. This is simply part of the FNC’s character and can be left as is or else molycoated to restore a heat resistance coating of beauty.

Conclusion

This article has described in detail the process involved in selecting and converting a semi-automatic rifle to select fire. In this case, Fabrique Nationale’s FNC carbine. The FNC meets the four primary criteria of a candidate weapon. It adheres very closely to the factory full auto weapon and requires few new parts to achieve a correct conversion…and the parts are on the market. Further, it uses the very common AR15/M16 20 and 30-round magazines while the availability of suitable milspec 5.56mm ammunition is a major plus.

Finally – and this is the most important point – high quality registered auto sears are fully available and RELATIVELY INEXPENSIVE!!! Most importantly, should you desire to convert the FNC to select fire it can be faithfully done to factory standard.

Enough said.

Check out Fabrique Nationale’s FNC and its conversion to select fire… give Curtis a call…and you will become a convert like me!

S&H Arms of OK
Attn: Curtis Higgins
PO Box 121
Owasso, OK
(918) 272-9894

Tampa Bay Military & Police
Supply, Inc.
Attn: Dana Reed
501 S. Falkenburg Rd.
Tampa, FL 33619
(813) 662-9433
fullauto@gte.net

Cole Distributing
Attn: Gary Cole
PO Box 50271
Bowling Green, KY 42102-2871
(502) 843-6844

As readers of SAR may know, I recently completed a military tour in Bosnia and was able to observe and handle many foreign weapons. One which caught my eye was that carried by the Belgium contingent – the Fabrique Nationale Carabine. Upon returning to America I kept on thinking about that FNC. I discovered they were available and decided (actually, my wife Linda gave me permission) to get one. A phone call to Gene Guilaroff, who has supplied me “black rifles” in the past, had an FNC Paratrooper with 18” barrel on the way to me.

After becoming quite familiar with my FNC, I wanted to learn more about it but quickly discovered there was little information available. Well, that situation has now ended with the publication of this two-part series on the FNC. This first article will provide a detailed overview of the rifle, including its background, technical details and operating characteristics. The second article, to be published shortly, will cover in detail its conversion to a factory-correct select fire weapon. Hint for all Class III enthusiasts: registered sears are plentiful and relatively inexpensive!

Installment 1 of the FN FNC in America.

Background

The birth of the FNC begins with its grandfather, the world famous FN FAL 7.62mm battle rifle. In the period 1963-66 as the arms market showed interest in smaller calibers, particularly the 5.56mm round, FN responded by designing the 5.56mm CAL rifle. Essentially the CAL was a smaller version of the FAL and continued to use the unique adjustable gas system. Unfortunately, the CAL was costly to manufacture/unreliable and therefore discontinued in 1975. It should be noted that 15-20 semiauto CAL’s were imported into America and sell (if available) for around $7500.

During 1974-76 FN redesigned the CAL into what we now know as the FNC. This was done for two reasons: 1) to compete in the 1976 Swedish arms tests and 1977-80 NATO cartridge evaluation trials; and, 2) to market a reliable 5.56mm rifle which could oppose the M16. Ultimately, in addition to Belgium, Sweden and Indonesia became licensed manufacturers of the FNC. At last count the FNC remains used by these three countries’ military forces and also is exported to parts of Asia and Africa.

Three importers are known to have brought semiauto FNC’s into the United States. Steyr of Secaucus, NJ and Howco of Laurel, MD brought in a total of about 1000 into the US during 1982-early ’83 timeframe. Gun South Inc. of Birmingham (later Trussville), AL imported approximately 5000 from mid 1983-88. When first imported in 1982 the price for an FNC was between $1000-1100. In 1985 this dropped to around $750 for either version to stimulate sales. In 1989 the importation of FNC’s, along with SIG, etc. was halted upon order of President Bush.

There were three imported versions of the FNC:

*Standard Model – Fixed stock with 18” barrel

*Paratroop Version 1 – Folding stock with 18” barrel

*Paratroop Version 2 – Folding stock with 16” barrel

Interestingly enough, while the folding/collapsing stock versions of military style weapons tend to be more rare, this is not the case with the FNC. Almost 90% of all imported FNC’s were the folding stock variation while the fixed stock comprised just 10% of the total. Also, the short 16” barrel is relatively uncommon and quite desirable.

Technical Details

Layout

The FNC is constructed of steel and aluminum alloys that are designed for reliability of operation and straightforward construction. Most of the parts are finished with a rugged satin black enamel which is baked on. The aluminum parts are black anodized while several steel items are dark gray parkerized.

With an overall length of 39.25” and unloaded weight of 8.3 lbs. (Para Version 1) it is of similar dimensions when compared to other 5.56mm rifles. The relationship of stock, trigger and handguard is excellent and readily lends itself to ease of handling and shooting. The handfilling front handguard is particularly well designed and remains cool to the touch even after periods of extended firing.

The trigger is designed by FN as a single-stage model and is fairly stiff. Trigger slack takeup requires 2.5 lbs. of pressure while sear disengagement needs an additional 8 lbs. to achieve release. Creep is typically .04-.05” which is well within specifications for a rifle designed for hard battlefield use.

The FNC is designed to use the NATO STANAG 4179 (Colt AR15-type) magazine. While a blued all-steel 30-round mag was originally available, it is generally hard to find and expensive. This is not a problem as the Colt 20 and 30-round versions work perfectly well and are found everywhere. For you serious collectors, the Beta-C mag should work properly in the FNC.

Receiver

The upper receiver is composed of stamped sheet steel with all welding performed robotically. The barrel extension, which includes the cartridge feed ramp, is spot welded into the front of the receiver. The rear of the receiver is given structural integrity by having the rear take down support also spot welded in. The rear sight assembly, too, is welded onto the receiver. To carry the bolt assembly, two U-shaped guide rails are spot welded inside the receiver. Next to the right guide rail is the ejector, which is riveted in place. Finally, to keep debris from getting inside the receiver there is a cocking slot cover which is spring loaded to ride over the cocking handle when the bolt assembly reciprocates.

The lower receiver is milled from aluminum alloy stock which is black anodized to reduce visibility. The magazine release is very similar to the Colt AR15 and is well positioned for one finger use. The trigger mechanism replicates the FALs’ and is easily accessible for maintenance. By rotating the safety switch vertically upwards it can be slid out to permit greater internal access for mechanism adjusting and/or replacement.

Barrel

The FNC’s imported into the US had two different length barrels. One was 18” and the other was 16”. Paratroop FNC’s came with both lengths while the standard fixed stock model came with the 18” version. Unlike the AR15, there has never been a heavyweight or “target” FNC barrel.

The barrel is hammer forged with a 6-groove RH twist which, is then hard chrome plated. Twist is 1/12” and designed to stabilize the US M193 55gr. bullet. It may not fully stabilize the newer US M855 62gr green tip slug. Interestingly enough, the Swedish Bofors-manufactured FNC (entered service in 1987 as the AK5) initially used a slow twist barrel due to humanitarian concerns about excessive wound trauma. They have since adopted the 1/7” twist as used on the M16A2 rifle.

The FNC barrel has a parkerized NATO-standard 22mm flash suppressor (LH thread!) which is very similar to the FAL “shorty” factory model. Flash suppression is adequate, but the main purpose of this device is to allow the mounting/launching of rifle grenades. Finally, the barrel is ribbed to support a clip-on bipod and front sling swivel.

Operating System

The gas-operated recoil system is a combination of the AK and FAL systems. A takeoff port in the barrel directs expanding gases through the gas block and into the gas tube. This tube carries the gas piston, which is part of the bolt carrier assembly. The gas slams into the head of the gas piston and forces the entire bolt carrier assembly to move backwards. As it begins moving to the rear, a camming action causes the bolt to unlock from the barrel extension and extract the spent cartridge case. Further bolt assembly movement causes the case to hit the ejector, recock the hammer and compress the recoil spring. The spring then drives back into battery the bolt carrier assembly, which strips off a fresh cartridge from the magazine and cams the bolt back into engagement with the barrel extension locking lugs. It is now ready for another round to be fired.

The FNC bolt is similar in size to an AR15 bolt and has two large dual-opposed locking lugs. The firing pin rides within the bolt, but is unusual in that it is retained by the bolt carrier and floats for 7mm. A firing pin spring is used so that an accidental inertia impact with the cartridge primer (which AR15’s are known to do) is eliminated. This firing pin is very thin and perhaps the weakest point in the FNC system.

Finally, the FNC gas system is adjustable in two separate ways. Should crud build up and more gas pressure is needed to cycle the action, an extension on the gas piston tube is rotated 90 degrees clockwise. This will cause the gas piston tube to close over an exhaust port located on the gas block and result in increased pressure being diverted against the gas piston head. The second adjustment is in regard to the firing of rifle grenades. By flipping up the grenade sight the gas is then cut off from flowing through the gas block and the FNC will not cycle. This permits the full force of the gas to be directed against the base of the grenade. Of course, a special ballistite (blank) cartridge is required to generate the high pressures required for launching.

Sights

Sights on the FNC are clearly in line with those of the FAL. The rear is an aperture type that flips into two positions: one for 250m and the other for 400m. It is protected from accidental knocks by two ears, which extend up from the base. Each adjusting click of the detent will traverse the bullet point-of-impact 1cm at 100m. The front sight is a spring-loaded post, which is also protected by two ears. Although there is no detent, each 1/4 turn of the post will elevate the bullet 1cm at 100m. While the sight adjusting function is performed with the combination tool, the Uzi SMG tool is also perfect for the job. Sight radius for the FNC is 20”.

Furniture

All the furniture on the FNC is rugged black plastic. The handguards are compression molded and riveted with brass nibs to steel liners. These liners give excellent structural integrity while being vented to dissipate the heat both forward and through the top. The pistolgrip is a direct takeoff from the FAL and is wedge shaped with a fairly steep rake to increase control while in rapid fire. The pistolgrip also contains the oiler/cleaning kit.

The sturdy folding stock is also a copy of the FAL paratroop unit. The two legs and buttpiece comprising the stock are made of aluminum, which has been finished in a baked-on satin black enamel. Also, the top leg of the buttstock is encased in plastic to reduce the effect of temperature extremes on the shooter’s face. The stock is fixed to the lower receiver via an aluminum mounting block which has been black anodized. To fold the stock, simply thumb aside the lock button, disengage the stock from the mounting block and fold against the right side of the rifle.

The fixed stock is also made of hard black plastic with a steel buttplate. It is mounted directly to the lower receiver via one screw. Swapping folding and fixed buttstocks is quite simple and requires no modifications to the bolt carrier, recoil mechanism, etc. Simply remove the screw, replace the stock, and reinstall the screw.

Spare Parts

Just recently the import of Indonesian-manufactured spare parts has taken place. Spare barrels, firing pins, magazines, tools, etc. are all available from Tampa Bay Military & Police Supply Inc. These items are officially licensed from FN and built to military specifications by the quasi-governmental firm of Bandung. Since Indonesia has been fighting terrorists and internal unrest for many years it is safe to say these parts have stood the test of time and will work quite well in the FNC. Two particularly interesting items are the 16” and 18” barrel assemblies with the 1/7” twist which will permit stabilization of the heavier M855 62gr. bullet.

Accessories

The FNC factory manual dated March, 1982, shows the following accessories to be available:

M16 Bayonet Adapter – This is attached to the barrel and permits the US M7 bayonet to be used. Otherwise, the FN “tubular” bayonet is used by sliding it over the NATO-standard 22mm flash suppressor.

Telescopic Sight – This is a superb 4×28 milspec scope manufactured by Hensoldt. It has the typical picket-post crosshair and sports an olive green finish. It is attached to the scope mount via two STANAG screws and is adjustable for windage and elevation.

Telescopic Sight Mount – This is a quick disconnect mount very similar to the SIG AMT design. The forward end of the mount is inserted into a cutout that is machined into a protrusion coming up from the barrel extension. The rear is then lowered until it lays against a dovetail which is part of the rear sight base. A lever on the mount is then pushed which cams into the dovetail. Neat, simple and very quick.

Bipod – This is a sturdy cast aluminum “claw clamp” design similar to the model used on the AR15. It functions by squeezing the spring-loaded legs together and placing the open mouth against the barrel. Releasing it will cause the mouth to close around the barrel and remain in place. With a working height of 11” it gives excellent support to the FNC.

Combination Tool – This tool is very handy for cleaning the gas piston, gas block port and adjusting the sights. Normally quite difficult to find, it is now being imported by Tampa Bay Military & Police Supply Inc. and an excellent addition to the tool box.

Operating Characteristics

The FNC is a fun firearm to shoot. Its simple, yet solid, construction gives it a balance and heft which yields confidence. Whether in the paratroop or fixed stock versions, it remains an excellent firearm to employ.

To load the FNC simply insert the magazine into the feed well and push until it locks into place. Grasping the cocking handle on the right side of the receiver, pull it to the rear and release smartly. A round will be chambered. Take it off safe, aim through the sights and press the trigger. Recoil is well dampened and presses directly back into the shoulder. Recovery onto the target is rapid for followup shots.

Accuracy testing with 210 rounds of first quality (not surplus) IMI M193 ball ammo provided by Cole Distributing revealed my particular FNC fired a consistent 10-round group of 2 1/2 MOA. This was with iron sights and stiff trigger, while the average velocity clocked at 3281 fps. The accuracy with this particular FNC/cartridge combination was outstanding and exceeds any military requirement I am aware of. One comment: many shooters avoid “surplus fodder” due to concerns about overpressure, corrosion, etc. This is clearly not true with Cole’s .223 IMI cartridge. It is very accurate/clean burning and is highly recommended!

For reloading purposes the FNC is not as friendly as the AR15. Most cases being ejected from the FNC are dented due to impacting the cocking slot cover. Unlike the H&K series of rifles, there is no optional ejection port buffer to snap on and reduce case damage.

Breaking down and cleaning the FNC is similar to the AR15. First, take out the magazine and make sure the chamber is empty. Cock the weapon and place it on safe. Push out the two captive takedown pins that connect the upper and lower receivers together. Grasp the cocking handle and retract the entire bolt carrier assembly towards the rear. As the handle reaches the cutout at the rear of the cocking slot pull it (the handle) out from the bolt carrier assembly. Use your finger to slide out the bolt carrier assembly from the upper receiver rails.

Next, press on the recoil spring retainer plate and rotate it 1/4 turn in either direction. This will disconnect the recoil spring/guide from its attachment point inside the gas piston. Slowly withdraw it towards the rear as spring tension is released. Finally, separate the bolt from the bolt carrier by rotating it 1/4 turn counterclockwise and remove it from the bolt carrier. Be careful the firing pin spring does not accidentally fall off the pin and get lost! Remove the handguards by snapping off their spring retainer clip located in front of the gas block.

Cleaning the FNC is very simple. Standard solvents and oils are used, but make sure all ammonia-based products do not come into contact with the aluminum lower receiver. It will attack non-ferrous metal! Cleaning the barrel from the breech end is simple and the only proper way to do so. Make especially sure you address the receiver extension where the bolt locks up as it will harbor a good amount of crud. Other places to make sure are clean include the hard chromed gas piston area, the gas tube it travels in and the gas block with its porting hole. For really stubborn carbon deposits in these areas I use a wooden popsicle stick or the combination tool to scrap them away.

Reassembly is the reverse of disassembly. Items to watch for include making sure the cocking handle is placed back into the bolt carrier assembly (it’s easy to forget) and the gas selector lever is placed into the “normal” and not full power position.

Conclusion

The FN FNC is one of the “best kept secrets” in military-style rifles to be imported into America. It is clearly one of the best. When comparing its cost to similar imports the true value of the FNC will become even more apparent. In fact, I consider it one of the few remaining “bargains” to be found. Where else can you get a firearm of this type from an internationally respected manufacturer for the price of a green label AR15?

Firing the low recoil and commonly available 5.56mm cartridge makes it a pleasure to shoot and even easier on the pocketbook. Further, its supply of high capacity magazines is assured for years to come. As an additional incentive, the import of licensed spare parts has begun and will keep the FNC running long into the future.

Fabrique Nationale’s FNC until now has been little known in America and deserves much greater respect than has been accorded. Belgium, Indonesia, Sweden and a host of other armed forces cannot be wrong. Now, with your knowledge of the FNC, you will not be either.

Stay tuned for a future article on how to convert the FNC to select fire – with registered transferable factory parts!

Arclight
Attn: Gene Guilaroff
PO Box 173
Alvaton, KY 42122
(502) 622-7309

Tampa Bay Military &
Police Supply, Inc.
Attn: Dana Reed
501 S. Falkenburg Rd.
Tampa, FL 33619
(813) 662-9433
fullauto@gte.net

Cole Distributing, Inc.
Attn: Gary Cole
PO Box 50271
Bowling Green, KY 42102-2871
(502) 843-6844
www.cole-distributing.com

This article provides an overview of what is arguably the highest quality military-style rifle to ever be imported into America – the SIG AMT. By understanding the background, technical details, operating characteristics and accessories of the SIG AMT you will gain a perspective into why it is considered one of the finest rifles of its type in existence. Have doubts about this grandiose statement? Then read on!

Background

During the period 1954-1957 the Swiss firm of Schweizerische Industrie Gesellschaft (SIG) designed an assault rifle which ultimately became the Sturmgewehr (StGw) 57. The StGw57 was in the 7.5mm Swiss caliber and borrowed ideas from the earlier Spanish CETME Model L and Mauser StG45 rifles. Chief among these ideas was using a receiver of stamped steel along with a delayed-blowback operating system comprised of a bolt assembly utilizing twin locking rollers. These locking rollers are most commonly seen today in H&K rifles.

The Swiss military used the StGw57 from 1957-1986 at which time it was phased out in favor of the newer StGw90 in 5.6mm GP90 caliber. However, throughout the distinguished 30-year service life of the StGw57 several updates to the basic design took place. These were done to increase its suitability for export purposes onto the global arms market. The updated StGw57, when exported out of Switzerland, then became known as the StGw510.

Options available within the 510-series included differing calibers, weight reductions, ergonomic refinements and simplified sighting equipment. There were five versions of the 510. These included:

510-1 Same as the StGw57 but renamed for export purposes
510-2 Lightweight version of the 510-1
510-3 Same as the 510-1 but in 7.62x39mm caliber
510-4 Same as the 510-1 but in 7.62mm NATO caliber
510-5 Same as the 510-1; Mexican Army prototype in 30-06 caliber

Throughout the period 1969-1989, SIG exported two versions of the 510 into the US. One was the 510-1 which was renamed for sales purposes as the PE57 and remained chambered in 7.5mm Swiss. The other was the 510-4. The remainder of this article will touch on the 510-4 and then detail its refined brother – the superb SIG American Match Target (AMT).

In 1969 several SIG 510-4’s, perhaps less than a dozen, were imported into the US. These were legally parallel to the FN “G” series rifle in that they were built around full automatic receivers with semi automatic internals. However, BATF approved these rifles as semi-automatics and therefore not falling under the restrictions of the NFA.

Later in 1969 SIG responded to emerging gun regulations in other countries (notably England and Italy) by slightly modifying the 510-4 to make it more “sporting”. This included deleting the bayonet mount and rifle grenade rings on the barrel. When imported into the United States this now became the SIG AMT. Benet Arms, SARCO, Osborne Brothers (import marking of “OSS”!), Mandall, SIGARMS and Golden State Arms all were AMT importers. It is known that 1,440 AMT’s were imported during the period 1969-1978. From 1979-1989 more AMT’s were imported although they were reportedly made up of parts which had been manufactured earlier. Total import of the AMT is estimated at 3,000 rifles for the years 1969-89. Even SIG does not know the exact number.

With a high retail price ($348 in the early 1970’s and $1700 in 1978) it was very expensive. Colt AR15’s and H&K 91’s were selling for well over a thousand dollars less during this same period. For these reasons – small supply and very high cost – the AMT is now one of the rarest military-style rifles in the United States. Market trends indicate it is now one of the most desired.

Technical Details

The AMT is superbly manufactured and finished in every respect. The traditional quality of Swiss workmanship is evident throughout all parts and functions of the rifle. After all, being directly related to the primary small arm of the Swiss military, it would have to be! Specifics on the major components of the SIG AMT follow.

* Layout – The AMT is not a big rifle, although it visually appears to be larger than it really is. Total length is 40” with an unloaded weight of 10 pounds. The charging handle is on the right side of the receiver and is extremely easy to grasp. The large ejection port is also on the right side and there is no ejector door as on the M16. The staggered-row box magazine comes in 5, 10 and 20-round versions although the 24-round 7.5mm Swiss PE57 magazine will fit and function correctly if it has the older metal (not plastic) follower. The hollow black plastic pistol grip is quite comfortable to use and has a removable endcap to allow storing the cleaning kit.

From a side view the AMT appears to be a square and perhaps bulky rifle which could be uncomfortable to use. This is definitely not the case as it very readily falls into your shoulder when firing. The relationship between buttstock, forward hand rest and trigger assembly are excellent. Overall fit and finish are the best I have ever see in any production rifle, anywhere. Finally, the major components of the AMT are all numbered to each other in traditional European fashion.

* Receiver – The receiver is essentially composed of three pieces: two end caps which are blued, and the parkerized central receiver section. The central section is stamped steel with several ribs to give rigidity and also perform a self-cleaning function. The front end cap is a cast and precision machined component which is spot welded to the central section. One unique feature of this cap is that the bolt locking roller recesses are contained in separate parts and held in place by circlips. When the recesses become worn simply pop off the circlips, install new locking recess parts, and replace the circlips. Your AMT is now ready for thousands of new rounds to be fired. The rear end cap is also spot welded to the central section and lends structural support while serving as a mount for the buttstock. Typical for the period, a carrying handle is mounted into the receiver and is placed where the AMT naturally balances.

The lower receiver is also of stamped and folded steel which has been parkerized a medium gray color. It operates in the same fashion as H&K rifles since it contains the trigger/safety mechanism and pistol grip. The lower receiver is retained in the rifle by clipping the front section into two flanges with the rear locked in by a single push pin. One unique feature of the SIG AMT is it comes standard with a winter trigger. Under normal operating conditions it is folded up against the right side of the lower receiver and out of the way. To use, simply snap it down and fire with your gloved hand. Believe it or not this winter trigger is so well designed it gives an excellent “feel” of the sear disengagement and fire control. Finally, a small square metal plate is visible on the right side of the lower receiver. The external side is painted white to signify the AMT is semi-automatic. If it was reversed to its normal gray parkerized color this would visually indicate the rifle was full automatic.

* Barrel – The blued steel barrel is 19.9” long and has four-groove rifling with a 1/12” twist rate. This is an optimum geometry for 7.62mm NATO slugs in the 150-165 grain weight range. Accuracy with milspec ammunition is excellent as my AMT routinely delivers 2 MOA with iron sights and my poor eyes. The barrel is threaded and torqued into the upper receiver and is covered for 1/2 of its length by a perforated aluminum barrel casing. This casing not only assists in preventing unwanted banging of the barrel during field use but also acts as a heat sink and protection against hand burning. It is easily removable and contains the front sight assembly, hand rest and folding bipod. The barrel is also threaded for a flash suppressor which closely resembles the M16 birdcage version.

* Operating System – The AMT fires from a closed bolt. In fact, the full automatic StGw57 and 510-series all fire from the closed bolt. Pulling back on the very large charging handle (it is shaped like a miniature beer keg!) and letting it fly forward to load a round into the chamber is a very satisfying experience as all bearing surfaces are finely machined. It feels like glass sliding on glass. The charging handle has a detent which locks it forward and therefore keeps it from cycling as the bolt reciprocates. Also, the chamber is fluted to aid in initial extraction of a spent cartridge. While these flutes are not as prominent as on the H&K, there are more of them.

The AMT’s delayed blowback system uses twin locking rollers. The bolt assembly is quite similar to the H&K system in that a smaller bolt head contains the locking rollers and extractor. The larger bolt body contains the firing pin and a protruding director shaft (acts just like the H&K locking piece) which causes the locking rollers to cam into their recesses at the moment of firing. After the bullet exits the bore and pressures drop to a safe level the bolt body moves rearward and pulls back the director shaft. This allows the locking rollers to release out of their recesses and the entire bolt assembly to continue recoiling back, cock the hammer, and compress the recoil rod/spring combination. Upon reaching the limit of travel the rod/spring drives the bolt assembly forward to strip and chamber a fresh cartridge. As the bolt assembly comes back into battery the locking rollers are then cammed back into their locking recesses by the director shaft and you are ready to fire another round.

* Sights – The front sight is a post which is protected by ears. Elevation adjustment is carried out by screwing the post the appropriate direction as on the AR15. However, unlike the AR15, traversing adjustment is performed by drifting the front sight base left or right. The rear sight is of the aperture type and is spring loaded to slide up or down a ramp which is ballistically matched to the 7.62mm NATO round. This ramp is graduated with detents from 100-600 meters. Sight radius is a generous 21”.

* Furniture – All AMT’s have wood furniture composed of a buttstock and two-piece forward hand rest. The wood is French walnut which is smoothly finished under a flat polyurethane coating. While both appear to be too small, this is definitely not the case. The buttstock has a hollow scooped from its midsection to allow an excellent cheekweld and proper alignment of eye-to-sight. The forward hand rest falls readily in place and is shaped to permit a good grip at a comfortable arm/body angle. Because of its straight-line design the force of recoil is directed against the shoulder muscle and the AMT does not unduly rise even in rapid fire. It is the softest recoiling 7.62mm I have ever fired. In comparison the H&K91 and FN FAL are like elephant guns.

Operating Characteristics

Firing the AMT is a pure joy. The balance and excellent ergonomics are hard to appreciate until you shoot several hundred rounds through it – at one session.

To begin, load up the magazine and insert it into the rifle. This is done in the same manner as a FAL or H&K. Place the forward part of the magazine into the mag well and rock it backwards until it latches in place. While keeping the AMT pointed downrange, grab the very large charging handle and pull it smartly to the rear. Letting it go will immediately place a round into the fluted chamber. At this point take it off Safe and start firing. You can always tell if the AMT is loaded as a cartridge indicator is built into the upper receiver. It will pop up a fraction of an inch if a round is chambered. In the darkness you can reach forward and feel it protruding. There is also a secondary cartridge indicator which is part of the firing pin lever and viewable/touchable through the ejection port.

As there is no hold open on the AMT the bolt will not lock to the rear after the last shot. It will close on an empty magazine just like the H&K. A hint which can prevent some minor marring is to not let the AMT “run dry” on a magazine. They are hard to find and expensive ($130 each) to purchase. As you come up on the last round it is better to remove the magazine instead of having the bolt slam into the magazine follower. Make sure you take care to manually eject the round which is still in the chamber!

Offhand shooting is perhaps my favorite position with the SIG as it really brings out the rifle’s inherent solid design. However, the factory manual states the preferred position is with the built-in bipod as it yields the greatest accuracy. While not disagreeing with this statement, it does sort of take the fun out of standing up and enjoying an extremely well built firearm with minimal recoil.

Cleaning the AMT is quite simple. First, make it safe by taking out the magazine and charging it. Place the selector lever on “S” and push out the single pin which retains the lower receiver. Swing down and remove the entire lower receiver. Depress the buttstock latch, rotate the buttstock 90 degrees counterclockwise and remove it. The recoil spring and rod will come out with the buttstock. Grasp the charging handle and slide it to the rear. The bolt assembly and charging handle can now be withdrawn from the receiver. Finally, split the bolt assembly by removing the transverse key. That is all there is for general disassembly. Detail stripping is not necessary except for once or twice a year.

Standard cleaning procedures should be used but make sure no aggressive chemicals such as carb cleaner, Tetra teflon solution, Gun Scrubber, etc. come into contact with the wood furniture. The fine finish on the wood may not be able to take these aggressive compounds. Also keep in mind the fluted chamber harbors additional crud and should be addressed a little more thoroughly. A US GI 7.62mm chamber brush will work quite fine. As the upper receiver is now wide open you can properly clean the bore from the breech side.

Accessories

The AMT has available several accessories which add to the enjoyment of owning this fine weapon. In addition to the 5, 10 and 20-round magazines there is also a cleaning kit, cartridge indicator hold open tool, locked breech gauge (similar to headspace) and sight adjusting tool. Since the AMT is still being sold in Switzerland the availability of most spare parts is assured. One location to get these parts is through SIG Parts Service of Auburn, WA, or you can file the necessary Form 6 with BATF and import them yourself.

Perhaps the hardest accessory to find is the very rare scope and QD mount combination. Reportedly there were about 100 scopes made in the 1970’s by the firm of Dr. Wohler from Kassel, Germany. Half of these went to the Chilean army for their use and the remainder were placed on the retail market. The scope is 4x with a 1” tube and comes with the traditional picket-post reticle pattern. It has a range adjusting knob which is cammed for the standard 7.62 NATO ball round.

The quick disconnect mount is equally hard to find. Fortunately, SIG Parts Service does a first class job of reproducing this mount which is currently available for $325. If you want to put optics on your AMT this high quality mount is clearly the way to go. Since the Dr. Wohler scope/QD mount are almost impossible to find, the use of a military 4x Hensoldt with reproduction mount would duplicate the original’s size and performance at less than half the cost.

Conclusion

The SIG AMT is one of the rarest military-style rifles in the United States. Imported in very limited numbers, the few which are available command a premium price and are normally found in excellent condition. Who would want to abuse such a fine example of the gunmaker’s art? Top notch machine work, solid design, excellent ergonomics, meticulous attention to detail and a host of similar thoughts crowd your mind when examining one. I should know – I bought my AMT after seeing it for only a few fleeting moments! Now, having been bitten by the SIG bug, how can I convince my wife to let me get that PE57… and mount a Gemtech suppressor on it… and… You get the idea.

SIG Parts Service
Attn: Estes Adams
PO Box 2631
Auburn, WA 98071-2631