RAFFICA

By Dan Shea

An example of sustained fire, the Somme, 24th August, 1916

The following extract is taken from the Official History of the Great War, and will serve to show what the water-cooled Vickers gun is capable of when the need arises.

The 100th Machine Gun Company was in a position known as Savoy trench. The Company had ten Vickers guns and was ordered to support an attack with rapid fire. It was necessary to neutralize an area and prevent any enemy crossing it for twelve hours. The area was visible at 2,000 yards range. Two Infantry companies were lent to stock the position with ammunition and water, whilst two men, working continuously on a hand-driven belt-filling machine, kept the belts filled throughout the period. Factory filled belts were not supplied until the 1930’s. 1,000,000 rounds; all but one belt were fired during the 12 hours. The ammunition expenditure was roughly as follows:

* Average rounds per gun 100,000

* Average rounds per gun per hour 8,300

* The best gun fired a total of 120,000 rounds (40 belts or 10,000 rounds per hour.)

There were no major breakdowns, and all the guns were in action at the end of the barrage, but the water only just lasted. It should be noted that the figure of 8,300 rounds per gun per hour included the time required for curing stoppages, loading belts, and relaying when necessary. In addition the water jackets had to be topped up, and the barrels would be changed about once an hour. The life of the barrel, under such conditions, it about 10,000 rounds, so over 100 barrels must have been used by the Company. – “Pistols, Rifles and Machine Guns” by Major W.G.B. Allen, s.a.c., The Loyal Regiment, 1953

Frequently, we hear discussions about what sustained levels of fire for machine guns are. I ran across the above description of an early area denial strategy that solely used the Vickers guns, and thought our readers might enjoy the data that had been extrapolated from the event on the Savoy Trench. Compare that to what our guns are expected to do in the modern military. It’s not really a fair comparison, because their machine guns could be water cooled, and weigh a hundred pounds with tripod etc. One really does give up a lot of potential when going to Air Cooled.

Right side view of the magazine-well section. Most semi auto or Class 2 projects are going to require saving this magazine-well, and perhaps the forward section of receiver tubing, although many choose to peel the destroyed receiver section from the trunion and cut the welds for the mag-well. Note the small metal nub at the front of the charging track; that locks the charging handle forward. The oblong slot at the front is the sling mount.
*(**Photo by Dan Shea courtesy LMO Working Reference Collection**)*

Q-I need some information on how to remove the barrel from a Yugoslav M56 SMG. This gun has a rather unusual looking barrel locking nut. Looking from the top there is a screw that obviously has to be removed. But there are also notches at the bottom on both the nut and the receiver that are aligned. Does this gun use a barrel washer system? Are any special tools needed to remove the barrel? Is there an exploded view drawing available?

A – There are a lot of the 7.62x25mm Tokarev caliber Yugoslav Model 56 submachine gun parts sets coming into the United States right now. They are a tube gun with roots in the German MP40, and are quite interesting. They make a good platform for a semi automatic rifle with either a longer barrel, or as a registered Short Barreled Rifle, as long as you have an ATF approved semi-automatic build-up for the fire control system. There have been a lot of questions on the barrel removal, and I checked to see if there were any resources on the Internet I could guide you to. Unfortunately, most of them had wrong information or missed the boat on how to disassemble this section without damaging the relevant parts, so, I just took a kit and set it up for proper parts recovery.

The small set screw you are referring to is at the center of this photo. It retains the threaded section of the barrel nut assembly and is the first thing to be removed. Take care on the removal and make sure your flat head screwdriver blade is perfectly fitted to the slot in the screw. Proper width and length are important in case there is resistance to removal, so you don’t strip this out. It will have to be drilled out if you tear the head. If it doesn’t give right away, put the Marvel Mystery Oil to it. It is probably not a bad idea to put this whole assembly in for a soak before you start. But many of the kits are very clean, and won’t really need that. Beyond that, a bit of propane heat could help. Remove the screw.
*(**Photo by Dan Shea courtesy LMO Working Reference Collection**)*

The target area. From the right: Barrel, barrel nut, washer, trunion body with groove and the receiver. Note the square cut in the center that is in the barrel nut, washer and trunion area. (Refer to the next photo to see these separate.) This cut is indexed by the set screw that has been removed, and its purpose is to allow a channel for the flat washer to be pin punched into place, thus locking the whole assembly from turning out. The first order of business after removing the set screw is carefully bending that washer back out of the channel so that it no longer interferes with turning. Once that is done, hold the receiver end of the piece in a non-marring vise, and remove the barrel nut to the forward position – it is standard right hand thread.
*(**Photo by Dan Shea courtesy LMO Working Reference Collection**)*

In this photo, all of the operations above have been completed. From the left is the trunion section with groove, then the flat washer, then the barrel nut. The barrel has been pushed into the trunion ready for removal. Normally the threads that the barrel nut turns on to would be visible on the outside of the barrel. As long as the ejector has been removed from the receiver, and the front sight and bayonet lug have been removed, the barrel can slip out to the rear now. (**Photo by Dan Shea courtesy LMO Working Reference Collection**)

The cut oblong barrel base can be seen fitting into the matching opening in the trunion. The barrel inserts in from the rear of the receiver and slides into place providing a very secure positioning of the feed ramp. The somewhat fuzzy part in the center is the ejector. The ejector is removed next by driving out the retaining pin. The ejector will block the barrel from coming out of the receiver section to the rear.
(**Photo by Dan Shea courtesy LMO Working Reference Collection**)

First, you have to understand that the barrel has to be removed backwards – out through the receiver. Outwardly, it camouflages that fact because the barrel nut looks like it holds the barrel in from the front. One would guess from looking at it that the barrel nut threads onto the trunion and secures the barrel: that is not correct. That rearward removal means step one is to drive out the pins that hold the bayonet lug and front sight on the barrel. Once these two items have been removed, then the barrel will be ready to remove to the rear. Follow the steps in the pictures and good luck on the project. I predict that due to the thousands of M56 available overseas or in the US already, that there will be some production semi autos as well.

Q-I couldn’t make out the details of the F1 submachine gun in Raffica (Vol. 9, No. 1, Oct. 2005, page 21) that Bill Vallerand was holding. Can you give us a better look at it?

A- The Australian F1 is a unique and interesting gun combining the features of the Sterling, the Austen and the Owen. They are very rare in the United States and I don’t recall seeing any registered transferable guns. I plan on doing a feature on the F1 in the future. I have watched for these in museums, and recently noticed one in the Pentagon foreign armies display cases. To your question, here are three pictures that should give you a better understanding of the outward appearance of the F1. (Photos are by Dan Shea, courtesy MOD Pattern Room)