During WWII, the Gewehr 43 (G43) was the German answer to American M1 Garands and Soviet SVT-40s. Along with parts and accessories, the rifle is highly collectible today. SARCO Inc. (Steen Armament Research Company) offers functional reproduction magazines for replacement or to save wear and tear on originals. The company, located in Easton, Pennsylvania, is one of the largest dealers in surplus war materiel in the U.S. The business collaborates with military arms collectors, shooters and military history re-enactors. This article compares a reproduction to an original “gcb” magazine. SARCO’s magazine’s dimensions closely match, and it functions without problems on an AC44 rifle. The markings are close but different enough for collectors to distinguish. However, the magazine catch area has thin metal in one area.

Physical Construction

The magazine body is dimensionally similar to the original. Despite sharper corners, one can still easily insert and eject the magazine. While feed lips are shifted slightly forward, they fed ammunition without pause.

Externally at the front, the two rivets are solid on the original, while hollow on the reproduction. At the bottom and sides, floorplate lips and over-insertion stops are similar to the original. At the rear, magazine catch differs notably. Two sides of the sheet metal body are folded together to form the spline. This is also where the catch is formed. The reproduction has a notch cut into the inside piece of sheet metal, and the outside piece is seemingly stamped to form the “V” shape. Consequently, there is precious little metal at the apex while magazine internals are exposed to the outside. The original does not feature this opening, and the author could not verify metal thickness at its apex. The SARCO representative reassured that the company has never had issues regarding this construction and has no history of returns.

Internally, the follower is of the same stamped metal construction as the original. While the stamped bits used to hold the magazine spring is shallower and smaller on the reproduction, there was no functional issue. At the follower tail, the original is fully welded and smooth whereas one can see the splits on the reproduction. Recoil spring is of similar gauge and length, with the same number of wind-ings. The reproduction floor plate is the two-ribbed type, with cuts in the same place, and is interchangeable with the original.

Markings

The reproduction’s markings are mostly correct but are different enough to allay fears of contaminating genuine pieces. The markings are shallower and lack tell-tale signs of stamping usually observed in originals.

The manufacturer code “gcb” denotes Ad. “Grohmann & Sohn in Würbenthal Sudetenland” is mirrored across both magazines in the same place. However, the original is marked only “K43” while reproduction is marked “G43/K43” in the same place. The original magazine also featured both “WaA892” Waffenamt on the bottom in line with the other markings, while the reproduction magazine placed one just under the front over-insertion stop. Lastly, the original Waffenamt has the alpha-numeric arranged in a slight curve under the Nazi eagle while the reproduction has them straight.

Function and Conclusion

SARCO’s reproduction magazine functions without hic-cups in the test rifle, a Walther 1944 manufacture (AC44). It locks into place with no undue wobble and removes cleanly with the magazine release depressed. Using Yugo-slav surplus 198-grain ammunition, it feeds reliably from the first to the last round. These reproductions represent viable, functional replacements while marked closely enough for passing inspection—the clear differences prevent pollution.

FOR MORE INFORMATION

SARCO Inc. e-sarcoinc.com

In 2018, the author mailed in his paperwork (a separate packet than the one used for rifles) and was given a randomly generated number in the low 3,000s. CMP called those numbers sequentially, and the buyer was given a choice of Service or Field Grade based on availability at the time. The author was contacted around middle of March 2019 and purchased a Service Grade pistol. It was delivered inside a large protective case marked with “CMP” on the outside and included a certificate of authenticity. The pistol is in excellent shape with little finish wear on the frame rails and no gas cutting of the breech face. 

Frame 

The frame was manufactured by Remington Rand (RR) in 1945, and most of the frame parts seem consistent. In front of the serial number, “NO.” instead of “Nº”is consistent with a late war RR. Proof mark “P” is behind the magazine release. “FJA” represents the inspection initials for Frank J. Atwood and is found on RR and Ithaca guns. The main spring housing has seven ribs which mark it as a late-war Ithaca part, while an RR part has eight ribs. Smooth contouring of the thumb safety matches another identifying point for RR. The trigger is a rounded, stamped and parkerized affair. The type 3 magazine release features a slot screw head. As expected, the slide stop and safety are serrated and not checkered. 

Grips with reinforcement rings were manufactured by Keyes as denoted by the star with a “K;” however, only the right stock has a part number denoting Korean War-era replacement. It is possible that the left is an original part with the right replaced when damaged. On the right of the frame, in front of the slide stop, one can find “A 8 80” under “M1911 A1 U.S. ARMY.” That marking is not parallel to the original serial number and seems deeper. This author can only guess this was the date for the rebuild; although “A” does not denote any familiar arsenal. 

Slide and Barrel 

Both slide and barrel are post-WWII GI replacement items. The left side of slide has drawing number “7790314” in large font, and the right side has “53397” which is the Cage Code for NUMAX ELECTRONICS INC in New York City. Since this is a post-war product, it is fully heat treated. Author has yet to learn the significance of “M” marked atop the slide, between ejection port and rear sight. When viewed from the top, the machining in front of the leaf is radiused and is the type used by Colt and US&S which was eventually adopted by all contractors; the original RR pattern had straight cuts. The front sight measures 0.08-inch wide, but the top was slightly peened, perhaps from rough handling. 

The barrel has a caliber and drawing number visible through the ejection port. At the bottom near the barrel link, one can find “73677” for DUROYD MFG CO INC on the right, and “M” “P” marked on the left. Rifling, crown and lugs are in excellent condition with minimal wear. The recoil spring guide is the late type with rounded legs, while the plug paradoxically was not punched to retain the spring. That makes the plug either an early production run example or a commercial one sourced outside government supply. The barrel bushing is unmarked. When in battery, the pistol rattles little with the barrel-to-bushing fit not excessively tight or loose. 

Shooting and Final Thoughts 

No malfunctions were experienced during a short range trip. The safety engaged and disengaged with authority and assurance. The trigger measured about 5.5 pounds. and featured a notable amount of creep. The trigger face fell at the middle phalanges, whereas the wider-gripped Beretta M9 fell at the joint between middle and distal phalanges. This author is very happy to add a genuine piece of Americana to his collection and looks forward to retelling its rich history to future generations. 

Most prepared citizens carry a handheld flashlight in addition to their firearm. This piece examines some of the current high-output (around 1,000 lumens) tactical lights while focusing on beam patterns, switch ergonomics and carry comfort. The tactical lights examined are: Streamlight ProTac HL-X, SureFire Tactician, SureFire Defender Tactical (E2DLU-T) and the SureFire EDCL2-T.

Beam Pattern and Vision

To draw an analogy between flashlights and cars, lumen is like crank horsepower whereas vision downrange is like wheel horsepower; the former is a figure on paper while the latter has practical impact. Crank to wheel horsepower is influenced by driveline loss, while lumen to downrange vision is influenced by beam pattern. 

Flood beam light trades throw distance for a wider field-of-view up close; Spot beam light allows one to see a small patch very far. The lights discussed in this article rank from flood beams to spot beams in this order: SureFire Tactician, SureFire EDCL2-T/Defender Tactical and Streamlight ProTac HL-X. 

The author compiled the following table from his own measurements 6m from a blank wall. Note that hot-spot measurement for the SureFire Tactician is approximate at best, since it has a very gradual falloff. In addition, patterns from the EDCL2-T and Defender are indistinguishable. 

To put those numbers into practical terms, one must consider self-defense use cases. One may walk under street lights (e.g., downtown after dinner), observe suspicious behaviour and employ light to identify if there are no opportunities to avoid the behaviour. Ambient light forms the “noise floor” from which the target “signal” must be raised, so that the signal-to-noise ratio is sufficient for proper identification. Given similar lumens, spot pattern focuses more light on a target (higher candela) to help “punch through” ambient light. This increased identification range better maintains separation from the threat. 

Conversely, citizens may face multiple attackers as criminals hunt in packs. At 10m, SureFire Tactician’s flood pattern allows positive identification of another attacker 5m laterally from the main threat. Role-playing the off-axis threat in that scenario, the author found his vision severely impaired by the Tactician’s flood pattern such that the citizen’s silhouette is hidden. With SureFire Defender’s spot pattern, the threat could still engage a citizen’s silhouette. 

Indoors, the spot pattern allows one to more comfortably clear deep corners and long corridors while the flood pattern feels less claustrophobic. In rooms with white walls or mirrors, both patterns must be bounced off a ceiling or floor to avoid blinding oneself. 

A strong spill can simplify shooting with handheld lights. Employing the FBI technique with spot patterns, the author instinctively steered the hot-spot onto the target while drawing and aiming; although another tester did not experience this. A flood pattern light allowed the author to solely focus on marksmanship. With the SureFire technique, the author found he must angle the light low to avoid dragging his trigger finger against the support hand; alternate placements drastically compromised support. Strong spill from a flood pattern sufficiently illuminated the target even with such a pointing error. 

All the lights except the Defender Tactical (E2DLU-T) have low output modes as task lights. The Defender Ultra (E2DLU-A), identical to the Tactical in other aspects, offers a low mode when the tail switch is clicked twice in rapid succession. The Streamlight ProTac HL-X’s 65 lumens prove great for walking around but are too bright for administrative tasks at close distance. The converse is true for the 5 lumens of SureFire’s.

Switch Ergonomics

The Streamlight ProTac HL-X features a click-type tail switch where light pressure provides momentary-only light, and press-until-click provides constant-on light. Placing one’s thumb across the switch with a low edge of crenellation against the distal and proximal phalange joint reliably activates momentary-only light without the possibility of constant-on for the straight-thumbed author, even with an uncomfortable amount of force. A curved thumb tester could activate constant-on light despite crenellation (see accompanying pictures for thumb shape differences).

There are three TEN-TAP modes: high/strobe/low, high-only and low/medium/high. Rapid momentary activation (taps) switches between submodes (e.g., cycle from high to strobe), while 10 such taps with the last one being a constant-on activation cycle between modes (“Streamlight TEN-TAP Programming,” YouTube, uploaded by Streamlight, Mar. 5 2019, youtube.com/watch?v=0czy-S10ca8). 

SureFire Defender features heavy crenellation, and the same aforementioned technique applies to activating momentary-only light. Like the ProTac HL-X, switch rubber is slightly tacky even with damp hands while the switch itself provides good audio and tactile feedback when it is in constant-on mode. While doing night shoot exercises, the author did not accidentally activate the constant-on mode after familiarization, and there was no doubt of constant-on when he did make errors. The aforementioned concern about constant-on and a curved thumb also applies to the SureFire Defender light. 

Pushing the tail switches of both the EDC2L-T and Tactician will activate momentary-only light, regardless of pressure; screwing in the cap activates constant-on light. The EDC2L-T features a “gas pedal” whereby a light push activates low output and a heavy push activates high output; minimal twisting activates low constant-on light while more twisting eventually activates high constant-on light. The Tactician switches output by screwing the head in fully for high and backed out slightly for low. Both lights exhibited a quirk where, if the tail switch was backed off constant-on less than 1/8 of a turn, one could press the tail cap (not switch) to activate the light. The author surmises this to be an unavoidable side effect of manufacturing tolerance. Both lights have exposed tail switches which facilitates employing the SureFire technique with rifles and pistols. The author’s bony hands preclude the SureFire pistol technique with the heavily crenellated Defender and make it difficult on the lightly crenellated Streamlight ProTac HL-X. 

Carry Comfort

All of these lights can be carried bezel-up or -down except the Tactician. Instead, it trades bezel-up-only for a stouter clip. The author found both bezel-up or -down to deploy easily. For bezel-up, he points his thumb along the light, grasps the body with other fingers, withdraws and rotates to face bezel downrange; this became second nature with some practice. 

Carrying in cargo pockets can be comfortable even with larger diameter or longer lights although drawing requires one to slightly stoop. This method also swings slightly when walking which reduces consistency when drawing. 

The author prefers carrying in the lower corner of his slash pocket, as it provides an easy index for locating the light. In this position, larger diameter or aggressively crenellated bezels have dug into his thigh when sitting and the light was carried bezel-down. He has carried all four lights bezel-up, with no accidental activation or lens damage. Comfort is a very personal quality, and these tactical lights provide options to fit various body shapes and dress styles. 

Conclusion 

All the examined tactical lights here are high-output, easy-to-use and reliable. Someone frequenting urban centers might prefer a spot pattern light (e.g., Streamlight’s ProTac HL-X) to better “punch through” artificial lighting, while another area with little light pollution might benefit from a flood pattern light (e.g., SureFire’s Tactician) for wider vision. Even with 1,000 lumens, these lights still cannot comfortably address adverse lighting scenarios such as a loiterer shadowed by a tree and overhead parking lot lights. These tools are no replacement for good situational awareness. 

Daily attire should also be considered; smaller lights better fit an office worker’s slacks, while larger ones can comfortably fit a tradesman’s belt. Given the plethora of options, the reader is sure to find a tactical light that fits his use case. 

Let there be light! 

DS Arms, Inc, provides a one-stop shop for surplus Israeli light-barrelled FALs. They sell both complete rifles and parts kits from which this author assembled his rifle, under supervision of Harold Adams (SBD Arms, Arizona). This piece discusses parts conditions across two kits, 922(r) compliance (18 USC §922) and a brief mechanical comparison with its predecessor: FN-49. 

Parts

The kit contains all necessary parts except barrel and receiver. The wood furniture contained a lot of Cosmoline, and one buttstock featured soldier carvings. Both stock sets are “C-”type with metal flanges and no cleaning compartment. One set of front handguards is cut only for one spacer around the gas tube; another set has two cuts but wear marks show it was only issued with one. 

The kits feature both vertical and horizontal receiver lock levers. Both lower trigger housings feature Hebrew selector markings as well as the distinctive Israeli selector. One kit had copious Hebrew markings across various parts, while the other had less. The finish wear matches service rifle expectations. 

The original “4-”marked front sight post proved so tall that the author must use 500m aperture to zero at 25m. DS Arms related that all kits contain similar height posts; thus they produced new posts as a remedy. Although any metric post (including the later “two-hole” style) functions, new production uses “square base” to keep the original look. Of the two new posts examined, one was trapezoidal in keeping with the original (thick base tapering to tip), and the other was uniformly thin. 

The original barrel was not provided; the supplied original gas block was still pressed onto a cut section of the barrel. DS Arms offers a new, light-profile, U.S.-made barrel with and without gas block installed; this author chose the latter for simplicity. This gas block matches the surplus one in featuring the latter style “closed” type wings. The barrel crown is hardly recessed, and the author covers that with a thread protector from a hardware store for storage and transportation. 

The new production, semi-automatic-only receiver reproduces exterior markings. It lacks the cut that allows the selector to rotate into full-auto position, and the material around the trigger axis pin is not milled to accept a full-auto sear. This unambiguously restricts the rifle to semiauto only. 

922(r) and Assembly

U.S. Code, Title 18, Part 1, Chapter 44, §922 typically referred to as 922(r), prohibits assembly of a rifle with more than 10 imported parts. As applied to this FAL, one only needs to exchange four imported parts; barrel and receiver are U.S.-made while muzzle attachment is absent. Generally speaking, the cost-effective route utilizes a magazine (3 parts) and pistol grip. On a quest to keep the rifle exterior as original as possible, the author kept his Hebrew-marked trigger (changing hammer and sear), utilized an Israeli-marked magazine with U.S. followers (DSA item #119120-K) and installed a U.S. gas piston (DSA item #019IS). Note that the Israeli gas piston is a special length that is neither in inches nor metric. 

To barrel a receiver, metric barrel shoulders are faced down until the gas port clocks correctly; variously sized locking shoulders are available to ensure proper headspace (similar to different sized SMLE bolt heads). This author elected to have DS Arms perform this process as he has no lathe access, and the ancillary equipment (e.g., barrel vice, headspace tools) is not economical to purchase just for one rifle. One must take care to include all required parts, else risk incurring surcharges.

Improved FN-49

FAL directly traces it lineage to the FN-49, a design started pre-WWII, evacuated to Britain and languished till 1949 and used primarily by “non-aligned” nations. The heart of the action remains the same: short-stroke gas piston with tilting bolt. FAL also carried over the same gas plug design: the Columbian FN-49 is marked “A” for semiauto operations, and “R” cuts off gas to launch rifle grenades. The Israeli FAL has Hebrew character markings for semiauto and unmarked for gas cut off. Both rotate 90degs to disassemble. 

The FAL exposed the gas adjustment sleeve, while the FN-49 covered its sleeve under the front handguard. While both ostensibly require a special wrench to turn, one could adjust the FAL sleeve with fingers (if loose enough) or with a flat-head screwdriver and mallet (if obstinate) as field expedient measures. The FN-49 sleeve is more difficult to work without the wrench. 

Early FALs, including early Israeli rifles seen in Six-Day War photographs, use “open” front sight wings like the FN-49. The FN-49 rear sight is integral to the action cover while FAL moved it to the lower. Although there is no discernible movement in the FAL upper-to-lower connection, there is considerable wiggle in the rear-sight-to-track fit. FN-49 has some lateral wiggle no worse than that of M1 Garand at high elevations. Both have small rear apertures that are similar in size to the small M16A2 one which the author found to be detrimental for rapid engagements. Both rifles have acceptable “combat” accuracy given the heavy single-stage triggers and non-free-floated barrels. 

In addition to reconfiguring the traditional stocked FN-49 to a pistol grip on the FAL, the main spring was also moved into the stock via a captured assembly and connected to the bolt with a “tail.” This arrangement is reminiscent of the Johnson 1941 rifle and eliminates the chance of flying springs when disassembling to clean. 

These improvements make the FAL easier to maintain while keeping the proven action. It is easy to see why the FAL achieved such success and became the right arm of the free world. 

Conclusion

DS Arms provides a one-shop stop for purchasing parts to build or to buy a complete Israeli FAL. Parts were in good service rifle conditions, and they assembled without trouble. The rifle functioned reliably on the firing line. The assembly process gave the author an appreciation of mechanical intricacies and added to the joy of owning a historical piece. 

Gunsite Academy is the oldest privately operated firearm training institution. Started by the legendary Jeff Cooper, this school prepares students for deadly force encounters rather than competitions. The competition-minded southpaw author attended a 5-day 223 carbine course (first of the series) with his Colt AR-15A2 carbine. 

Knowledgeable instructors, detailed instructions and ample facilities provided information that cannot be gleaned by merely reading and practicing on “flat ranges.” While the author discovered gaps in his low-light and CQB skills, he expects every student to discover his own shortcomings and to leave Gunsite with the necessary redress. Here are some lessons learned. 

The Mindset 

A phrase often repeated by instructors was, “this is a fighting school.” “Diligentia, Vis, Celeritas” (“Accuracy, Power, Speed”) form the Gunsite triad. Since no two problems are alike and there is no cure-all, this course teaches “many ways to skin a cat” albeit with their own trade-offs. 

Instructors induced stressors to ensure performance under pressure. Lower on the pressure scale, the same drills were not consecutively called in order to maintain vigilance. Higher on the pressure scale, the author experienced precipitous performance decline during the culminating exam. While satisfactory during warm-up practices, the author’s trigger control declined during time-pressured sessions, proving Gunsite wisdom: “Speed is the devil.” 

As trouble travels in packs, students are constantly reminded to search and assess. Gunsite teaches that shooters should follow the target to the ground with a finger on the trigger in case the threat resurges, before sweeping laterally (finger off trigger) and repeating with every elevation change. Compared to a weekend course, 5 days afforded many repetitions to form new habits. 

Stopping Threats 

To effectively stop threats, one must balance speed with accurate shot placement to the upper chest or soft tissue area of head. The upper chest presents a larger area, but the effect is delayed. Soft tissue of the head (so named because eyes and nose offer an unfettered path to the brain) is significantly smaller with little margin of error, but the effect is instant. Inside 15 yards, the author felt confident aiming for the head at speed, even with iron sights. At 25 yards, he was more comfortable with speed and margins of the upper chest. 

At “bad breath” distances, sight-height-over-bore means point-of-aim must be higher than desired point-of-impact. This holdover differs between rifles, optic configurations and zero distances to name some factors. Using the instructor’s recommended 50-yard zero (yielding less than 2 inches of deviation between point-of-aim and point-of-impact out to 200 yards), the author found the tabulated aiming references to work well with his AR-15-A2. 

Manipulation 

Gunsite Academy taught students to visually and tactilely confirm manipulations, such as loading and malfunction clearing, for both low-light use and safety assurances. The author interpreted this methodical approach to value certainties, purchased with some up-front time, to avoid surprises “for want of a nail.” 

To build this certainty, magazines are pushed then pulled to confirm proper seating. To confirm proper feeding, if time permits, students are taught to remember which side of the magazine the top round resides; seat magazine; chamber; then withdraw magazine and confirm the top round shifted to opposite side. The author appreciated this technique not only for low-light but for rifles with deeply recessed ejection ports (e.g., HK MP5, FN F2000) that make “brass check” impossible. 

When practising speed and partial magazine reloads (aka tac-load or reload with retention), the author experienced wrist fatigue. Mild fatigue prevented him from pointing the rifle at the threat while reloading; rotating it up and into his “workspace” eased burden but cost time. Severe fatigue prevented the magazine from seating during bolt-forward reloads, even with less-than-full magazines. To keep plodding on, the author placed his primary hand atop upper-receiver for leverage. While the author strengthens his wrists, he will ponder whether to lock the open bolt before reload as a general policy; he already observes this for HK G3 and MP5 as they lack last round bolt-hold-open. This exchanges the possibility of one (chambered) round for the certainty of a full magazine. 

To clear malfunctions, Gunsite teaches immediate action drill (Push-Pull-Roll-Rack- Assess) with additional steps to clear double-feeds. Push-pull ensures seating; slap does not confirm seating and can cause top rounds to jump feedlips and further foul action if the bolt were stuck to the rear. Roll carbine until ejection port faces the ground; this eases egress of offending rounds. Rack to clear chamber. Assess situation, as it may have evolved such that shooting is no longer warranted. 

A bolt not returning home during rack indicates double-feed, and one should first lock the open bolt, withdraw the magazine, insert a hand through magazine well to clear action, rack to clear chamber and finally reload. When the author unexpectedly experienced a double-feed, he visually identified it while his mind started taking shortcuts. After he fouled the sequence, all focus was directed at the rifle with no focus left for situational awareness. This experience illustrated the importance of a well-practiced and methodical checklist. 

Being ambidextrous, the author switches shoulders when slicing corners to reduce exposure. The instructor pointed out that doing so rendered one unable to respond for the duration (about two seconds) if a threat unexpectedly presents itself. As a testament to instructor caliber, Gunsight also taught the author an impromptu lesson via learning-by-doing: if one intends to shoot ambidextrously, one should be equally proficient at shooting and manipulating from either shoulder. When the author was shooting from support-side (right), instructor unexpectedly called various reload 

and malfunction drills. While fumbling, the author learned that placing all magazines on his right side meant none were at hand for a right-handed reload. As such, he supported his rifle with his left hand on the handguard so the southpaw manual-of-arms can be used. 

Shooting Positions 

For brevity, this section only covers a few tips. One such tip concerns how to quickly mount a rifle from low-ready: place buttstock toe high up into shoulder pocket such that comb contacts chin for a touch index. This helped the author consistently acquire proper sight alignment and sight picture, yielding faster reaction times and more accurate shot placements. 

Decidedly unconventional positions where a rifle is rotated 90 degrees (ejection port facing sky or ground) were introduced for use in urban environments or VTAC barricades common for many matches. To shoot over low cover (e.g., high roadway curbs, low flower beds), students learned supine prone. Lying on the back, students rolled toward the target just enough for rifles to fire over cover. To shoot through low openings, urban prone rotates a standing position orthogonally so the spine parallels the ground with the rifle merely inches off terra firma. Support hand is balled under handguard for support. Although not covered in class, the lower body can be further tucked behind cover such as a brake disc and rim to shoot under vehicles. The author also found success adopting this position for use with the bottom row of a VTAC barricade. In contrast, SBU prone adopts a traditional prone position with shoulders square to target, but the rifle is turned sideways and placed over shoulder to shoot through lateral slats such as those on a second-to-bottom row of a VTAC barricade. Also not covered, the same upper body position reused in kneeling allows one to shoot over vehicles with minimal head exposure; rifle rotation places bore at same elevation as the eye. With all three positions, sight-height-over-bore induces lateral offset which must be learned through practice. This course only afforded one practice session for these positions. 

For the outdoor-minded student, instructors discussed impromptu rifle support on vertical and horizontal surfaces familiar to Precision Rifle Series shooters. Outdoor Scrambler and Military Crest outdoor simulators provide ample opportunities for practice. Many other instructions are not mentioned here for brevity, but all are eminently useful and well worth the price of admission. 

Low-Light Exercises 

The course included an evening session to introduce low-light shooting. As twilight did not start until around 19:30 during summer, the session was limited to roughly 90 minutes (hampered by range limitations). Instructors discussed handheld light features and stressed simplicity in operation. 

Exercises during twilight, without illumination, showed limits of human vision and iron sights. Targets featured a black sweater and drawn revolver; the former made the black front sight post all but invisible while the latter proved difficult to identify past 7 yards. Since identification is a necessary precursor to engagement, this illustrated the attacker’s advantage and likely engagement distance. 

After darkness fell, the instructor stood behind students and swept his flashlight across them to simulate vehicle headlights, allowing a fleeting engagement. The author’s own backlit shadow obscured the front sight post, but he muddled through with body indexing, thus proving the worth of tactile memory. However, electro-optics would drastically improve matters. 

As befitting an introductory-level course, only handheld lighting techniques were discussed. Flashlights are common household items and are normally carried by prepared individuals as part of their daily kit. Even when equipped with weapon-mounted lights, handheld techniques are useful in case of malfunctions. 

Harries technique for rifles is analogous to that for pistols. An arm with light forms an “iron bar” that pulls against rifle magazine well, preferably at a point closer to the elbow than the wrist for strength. While this requires a bladed stance that leaves recoil-control wanting, the author found thumb activation of light intuitive and sight picture stable. 

The SureFire technique pinches the light between index and middle fingers of the support hand while bracing the tail switch against a vertical surface (e.g., magazine well or vertical foregrip) for weapon support. Curling one’s fingers towards the palm activates the light. 

The author found superior stability and recoil control, but one of his lights gave inconsistent activation. Pelican 2360 featured a low-profile tail switch; this required precise placement when pulled against a flat AR-15 magazine well in order to activate. A convex thumb pad or ribbed magazine (e.g., “Circle 10” magazine for Arsenal SLR-106 as pictured) provided reliable activation. In contrast, the Pelican 1910 tail switch protrudes further and activates reliably with this technique. It should be noted that lights with shrouded tail switches (e.g., SureFire Aviator) are incompatible with this technique. 

This session’s farthest distance was 15 yards, presumably to accommodate lights with low output and/or reach. The author’s two-AA-powered Pelican 2360 casts a spot beam with little spill, trading situational awareness for farther reach. His one-AAA-powered Pelican 1910 casts mostly a flood beam with short reach. His weapon-mounted, two-CR123-powered, SureFire X300 Ultra has significantly brighter output with a wide spot beam that amply covers a torso at these distances; there is abundant spill for situational awareness as well. Note that the X300, designed for pistols, trades reach for wider spot beam and more spill when compared to the rifle-oriented Scout series. The light was mounted to front sight block via Midwest Industries MCTAR-04. 

Readers are encouraged to experiment in a safe environment to find their own preferred technique. Facilities that allow night-time shooting are scarce, and indoor ranges with dimmed lights may be a useful substitute. 

Indoor CQB / Room Clearing 

The essential lesson learned regarding single-person CQB is to avoid it altogether unless there is an overwhelming imperative such as family member in imminent danger. While the author learned a great deal about footwork and path planning, he was disconcerted by the inevitable exposure to uncleared spaces. 

This course taught the proper way to slice corners. One should take small lateral side-steps until the edge of a potential threat is seen. Then, without pause, lean out to assess and engage if necessary. To avoid crossing one’s feet and failing to lead with foot closest to corner, one should lead with left foot when slicing left. In addition, do not move back behind cover when a potential threat is seen; this allows the threat to aim in with disastrous consequences. 

Instructors emphasized proper path planning to reduce uncleared spaces into manageable problems; although there are still inevitable “soup sandwiches” that illustrate why single-person CQB should be avoided. Students learned to approach doors from knob side, open authoritatively, then step back and slice corner as described above. Approaching from hinge side is not ideal, as feet or a shadow visible through gaps can alert threats and allow them to aim in. Another imperative is to properly plan footwork and a path for the entry itself. Lining up parallel to a wall and leading with the foot closest to the wall, move directly to opposite deep corner. Since average doorways (“fatal funnel”) require two steps to transit, it gives time to assess and address threats in the deep corner. On the third step, feet are properly positioned for pivoting toward the other deep corner while assessing the rest of the room. 

Gunsite shoot-houses provide scenarios for putting lessons into practice. The author learned that he moved too fast; when combined with fixating on one uncleared space, he was caught off guard by another threat. Additionally, he forgot about sight-height-over-bore when leaning around cover, so projectiles impacted the door frame and deflected from point-of-aim. His liberal expenditure of ammunition, combined with his forgetting to perform partial-magazine reloads, led to an empty rifle while engaging multiple targets. As he had practised his pistol transition without incorporating movements, he also didn’t move during the scenario despite kneeling to reduce his profile behind a dinner table. These lessons alone are well worth the tuition. To remedy these shortcomings, the author practices with multiple magazines loaded with a small and random amount of ammunition to force unexpected reloads or pistol transitions. 

Threat identification is a vital, but little practised, part of deadly force encounters. Most “flat-range” sessions, including competitions with no-shoot targets, only exercise the Act part of the Observe-Orient-Decide-Act loop. The author discovered this deficiency during the shoot-house scenario: his observation and decision time felt slow and required mental focus instead of being an instinctive action. Indeed, he failed to properly identify a suicide bomber (requiring a headshot) under pressure of multiple target engagements. Other students indicated this to be a common theme. A remedial drill would be posting targets with different numbers and having a partner call a random number; the trainee must search for and engage the correct number. 

This course only afforded one shoot-house scenario. For a “real world” application, the author surmises there is higher likelihood in clearing a room than shooting 100 yards. A shoot-house offers unique training opportunities not available elsewhere due to range constraints; the author learned important lessons in this scenario. 

Colt AR-15A2 

Overall, the AR-15A2 did not experience major deficiencies throughout the entire course. A2 iron sights were not an insurmountable handicap. For headshots up to 15 yards, the rear aperture could be ignored if the mount were consistent. At 25 yards, the author required the proper front and rear sight alignments to achieve good results; electro-optics, such as red dot sights, could alleviate this. At 100 yards, the author found more success with the small aperture than the large one. With no time pressure, he was able to produce similar group sizes with both, but the large aperture produced impacts almost 1 foot lower. At further distances, he had trouble focusing on the front sight; however, instructors’ coaching built his confidence using the iron sights. 

A light (aka A1) profile barrel, comparable to other service rifles such as AK-74 (5.45x39mm) and G36 (5.56x45mm), reduced weight and made long shooting sessions enjoyable. The author did not experience point-of-impact shifts attributable to thermal effects, as any were masked by shooter error. Of the three broad-categories of barrel profiles tabulated, the author favors light profile for carbines as it staves off fatigue and quickens target transitions. While profile affects thermal properties and accuracy potential, it is only one of many factors in the complicated relationship (see Chiu, Alton. “The ‘Proof’ Is in the Precision Proof Research Carbon Fiber Barrel.” Small Arms Review, Vol. 23, No. 7, pp. 50–55). 

The author used his Geissele Hi-Speed National Match two-stage trigger installed with “DMR” spring set for a 3-pound first stage. Second stage was set at 8 ounces and creep removed with internal adjustments. This provided predictable trigger breaks on-demand, affording precision in unstable positions or elevated heartbeat. The author credits this trigger with completing the outdoor scrambler fastest in his class (67.2 seconds with all first-round hits), earning him a Gunsite challenge coin. 

Final Thoughts

Gunsite’s professional and always cheerful instructors facilitate absorption of material developed with a combative mindset. As a competition-minded shooter, the author found many topics illuminating. However, 5 days aren’t enough to introduce, much less master, materials, and he would have liked more shoot-house scenarios. He sincerely believes students of all skill levels will find this course enlightening and fun.

For more information, see gunsite.com.

Conventional wisdom trades barrel weight for accuracy and precision. Proof Research combines these attributes in its composite carbon fiber and 416R barrel. Through interview with Proof Research and the author’s own rudimentary math, this piece briefly explores the physical and thermal properties affecting accuracy and precision, as well as how Proof Research mitigates these concerns. Performance was evaluated over a 65-round string using a 1:8 twist, 16-inch AR-15 barrel with an intermediate gas length (PN 101599).

Barrel Harmonics

An aphorism goes that all models are wrong, but some are useful. This section develops a wrong but useful “back-of-the-napkin” model to illustrate the vibration characteristics between lightweight and tar-get profile steel barrels. Generally speaking, less vibrations yield better accuracy, but the exact relationship is a complex subject requiring proprietary knowledge not available to the author.

Firing a cartridge forms an impulse event that spreads energy across the frequency domain and excites all structural modes. A free-floated barrel, with uniform profile and material, can be modeled as a uniform cantilever beam. The fundamental frequencies can be written as follows:

f is the frequencies (Hz), K is a constant with values 3.52 for primary, 22 for secondary and 61.7 for tertiary mode. L is the beam length (m), E is Young’s modulus (Pa), g is acceleration due to gravity (m/s2), and m is mass per unit length (kg/m). I is the area moment of inertia (m4) computed as equation 2.

Assume 4150 steel with a nominal 200 Gpa, 16-inch barrel length, 0.224-inch inside diameter. For lightweight profile, assume 0.625-inch uniform outside diameter. For target profile, assume 0.936-inch uni-form outside diameter. The vibration frequencies can be computed as follows.
One could compute the pure bending tip deflection from frequency using the relationship below.

but the results would be disproportionately small to real-world deflection observed in slow-motion video footage. This is because the bar-rel experiences tension (recoil and Newton’s First Law of Motion: The Law of Inertia), torsion (imparting bullet spin and Newton’s Third Law of Motion: For every action there is an equal and opposite reaction), bending (gravity), as well as axial and hoop stress (gas pressure). Thus, it moves in more of a circular cone motion than mere whipping in a vertical plane. These complex interactions are best solved with Finite Element Analysis not available to the author.

One can still grasp the relationship between barrel profile and harmonics using these equations. A thicker profile increases the area moment of inertia, making it stiffer. This increases fundamental frequencies and reduces deflections, agreeing with the conventional wisdom that one trades weight for accuracy and precision. A Proof engineer indicates that while this generally results in better accuracy (ceteris paribus), there are many other factors and interactions. It is important to note that this relationship is not directly applicable to comparing a Proof composite barrel against a similarly weighted steel barrel, as their Young’s modulus differ.

Proof composite barrels are made of reduced contour 416R steel, then helically wrapped with continuous fibers on a computer-controlled winder. The company claims “the aerospace-grade carbon fiber we use has a specific strength up to 30 times that of stainless steel and a specific stiffness up to 7 times greater than steel” (Proof Research. (2019). Composite Rifle—Proof Research. [online] Available at: proofresearch.com/the-science/ [Accessed 14 Mar. 2019]). The author found this statement insufficient for “back-of-the-napkin” performance comparisons. First, specific strength is force per unit area at failure divided by density (Nm/kg). Since forces experienced at firing should not approach

failure, this metric is not directly applicable but merely hints at the improvement. Second, specific stiffness is stiffness (force divided by deflection) to weight ratio, and the statement specified neither the mode (e.g., tension or torsion or bending) nor dimension. Note the nominal density difference between carbon fiber (1.6 g/cm3) and steel (7.7 g/cm3) already accounts for a factor of 4.4. Lastly, the composite barrel has an unknown internal profile that precludes any reasonable computation. The author had requested but not received more information from Proof Research due to the proprietary nature of these details.

At this point, the reader may be frustrated with the qualifications and ultimate inability to provide a clear and direct comparison between steel and composite barrels. The author promises recompense by way of an unequivocal demonstration in the shooting section.

Thermal Effects

This section examines the detrimental effects of heat over a long string of fire, and how Proof both mitigates and delays that. The vibrational characteristics previously discussed could be considered constant across the working temperature of a barrel, as both Young’s modulus and dimensional changes are minor.
On the other hand, manufacturing inadequacies can degrade accuracy and precision as the barrel inevitably heats up. Bore dimension changes can cause varying bullet start. Residual stress from rifling can deflect the barrel. To mitigate this, Proof uses 416R steel ordered from foundry to spec, then performs all other steps (e.g., cutting, rifling, lap-ping, etc.) in house so as to maintain tight tolerances. Proof Research claims a very stress-free process that results in uniform and repeatable bore and groove as foundational elements to accuracy. The same process is used on both composite and steel barrels.

Another mitigation is to expel heat quicker, so as to delay the onset of degradation. Although the barrel conducts heat into the receiver, the contact area is the same between different barrels’ profiles and is thus omitted from this discussion. Consider the free convection transfer rate in equation 4 and the black body radiative transfer rate into vacuum in equation 5,

where q is transfer rate, A is barrel surface area, Tb is barrel surface temperature, and Ta is ambient temperature. One can deduce that a larger surface area (i.e., thick profile barrel) cools faster.

Another consideration is the efficiency in transporting heat from where it is deposited (chamber and bore) to where it is dissipated (surface), a small pot. Heat transfer from the case wall and gasses to the chamber and bore are conductive and forced convective respectively. Their rates depend upon bore temperature, which differs between barrel profiles due to their different cooling rate, making a study of temperature versus round count difficult.

Proof Research promotes surface cooling with a thick profile while speeding the transport of heat from the chamber to the surface with a carefully designed helical fiber wrapping pattern. Because the chamber end of the barrel experiences hot gasses longer, its surface temperature 1/2×28 threads on the muzzle. Gas block area comes dimpled.

is higher than the muzzle end. The fibers diffuse heat along the length of the barrel to even it out and promote cooling. Furthermore, the carbon fiber and resin are designed to expand at the same rate as steel, so as to prevent de-lamination and point-of-impact shift. Although Proof declined to provide test data, it assured the author various contours of steel and composite barrels were tested in order to substantiate its claim of faster cooling.

Lastly, one should be reminded that factors external to barrel (e.g., receiver or stock contact point) can also result in thermal-in-reduced, point-of-impact shift. For example, M1 Garand match modifications ensure the upper handguard (clipped to barrel) does not contact the stock while the front handguard (attached to lower band which pulls against the stock) should not contact the barrel (Roberts Jr., J.B. “Accurizing the M1 Rifle.” The M1 Rifle, An Ameri-can Rifleman Reprint: 16. Print). As detailed in the shooting section below, the author discovered contact between his AR-15 gas key and gas tube, and this likely induced vertical stringing and lateral group shift.

Test AR-15 Barrel

Since the claims of Proof Research are difficult to substantiate with rudimentary models, the improvements must be observed in action. After all, the proof of the pudding is in the eating. The bar-rel chosen is a 16-inch, 1:8 twist, intermediate gas length composite barrel with a .223 Wylde chamber. Intermediate gas system is 1.5 inches shorter than a rifle-length system and longer than a mid-length one. Not being standard, a gas tube is also supplied. The gas port journal measuring 0.75-inch diameter is fully stainless steel and is dimpled for a set screw gas block; although the author utilized a clamp type adjustable gas block.

Proof Research offers both steel and composite barrels because light-ness is not universally desired. For carrying across mountains or burning through a close-quarters stage, low weight affords comfort and agility. After all, an old joke goes that an M1 Garand weighs 9.8 pounds with the decimal point falling out somewhere along a road march. Opposite is true for precision (e.g., PRS) rifles where weight increases polar moment of inertia and steadies an unstable shooting position such as off-hand or barricade. Author found the composite barrel to be a good compromise between steadiness and agility. For action matches, the rifle felt quick-to-hand even with multiple optics attached. For PRS matches, forward weight from a bipod and suppressor added steadiness.

Test Procedure

To evaluate both accuracy and precision over a long string of fire, the first 30 rounds were fired in five-round groups. These illustrated performance typically seen by most users. Thirty rounds were then fired in quick succession to generate heat, and the test concluded with five rounds fired in a group in order to highlight thermal effects.

The author fired from a prone position supported by the bipod and rear bag with a 10x scope at a 50m distant target. The human element was consciously added to observe mirage effects and to verify if the shifts were buried within discernible difference. The author fired at a cadence reserved for rapid fire portion of NRA high-power rifle matches, roughly one shot every four seconds. A pace of one round per second was used for the 30-round “mag dump.” There were magazine changes between each of the five-round groups, but the bolt was closed to minimize chamber convective cooling.

Results and Discussion

A peculiar lateral left shift and vertical stringing were noted when the test was first conducted. This was likely linked to heat as the effect showed in both rounds 26-30 group and 61-65 group. With the help of a Proof Research engineer, gas tube to gas key contact on the left and upper portions (looking from chamber to muzzle) was identified as the likely culprit. This data set is titled, “Rubbing Gas Tube” below. The clamp-type gas block was realigned and the gas tube slightly tweaked so the bolt carrier group slides home without shifting or resistance. The test was repeated and data presented with the title, “Aligned Gas Tube.” Considering the first 30 shots, the Proof barrel exhibited remarkably good accuracy and precision. Screening out the 26-30 group with the rubbing gas tube, both datasets exhibited point-of-impact shift within 0.2 Miliradian (MRAD) in horizontal and vertical directions. With a standard deviation of 0.1 to 0.2 MRAD, one cannot conclude the shift to be statistically significant. Putting it plainly, the author reasonably expects the first 30 shots to be within a 0.2 MRAD area. Note that although the adjusted gas tube data showed more shifts, it is likely due to the author committing shooting position errors.

Group centers for rounds 61-65 in both datasets are interesting. Lateral offset in the rubbing dataset is likely due to a rifle installation problem and not indicative of barrel performance. After correction, this group still showed an up-shift which is likely due to a barrel heat mirage. The author noted a heavy and boiling mirage developed during the 30-round “mag dump” and persisted into this last group. This mirage carried the target image high, causing the user to aim high, and, consequently, bullet impacts were high. The lateral offset is not likely a mirage effect but a position or natural point of aim error due to user fatigue. There were baffles on either side of the rifle to block wind. The gas tube adjustment also shrank vertical dispersion in this last group to be in line with the rest.

Infrared thermometer data was recorded on both the Proof Research composite and steel lightweight barrels but not presented in this piece owing to difficulty in meaningful comparisons. Chiefly, it was impossible to maintain the same timing of shots, ambient temperature or radiative heat from the sun. Infrared thermometer measures thermal radiation and is calibrated on a certain emissivity value. Differing barrel material has differing emissivity and does not allow for a direct comparison. Thus, this data did not add value to this discussion.

Conclusion

Proof Research’s composite barrel is a happy combination of light weight, accuracy and precision. Meticulous and stress-free manufacturing, combined with carbon fiber engineered for superior heat dissipation, produced an accurate and precise barrel even through a long string of fire. Although direct comparisons between composite and steel barrels proved difficult without the necessary but proprietary data, a shooting test unequivocally demonstrated its accuracy and precision. Despite carrying a hefty price tag (MSRP $920 USD), the author found the composite barrel a very worthwhile addition on his modern sporting rifle used for both precision and “run-and-gun” tasks.

Even with the prevalence of instructional videos on the internet, there is tremendous value in hands-on training with an esteemed instructor like Ernest Langdon. The author attended Langdon’s Tactical Pistol Skills class, and this piece recounts his analysis-driven lessons.

Analytics

Langdon was an instructor for the High Risk Personnel course during his tenure in the US Marine Corps. He attended various shooting schools, analyzed their techniques and fused together highlights for implementation with the USMC. He continued this intellectual approach on the competition and instructional circuit with much success, earning 10 National Championship Shooting titles and two World Speed Shooting titles.¹ At each segment of class, Langdon concisely presented his preferred techniques and their rationale. The author found this effective in facilitating material absorption and preventing a “cargo cult” of blind followers.

Analysis requires data, and Langdon expounded upon the need to track the sights before and after trigger break to gather data. Sight alignment and sight picture at trigger break allow one to “call the shot,” and this early information enables quicker re-engagement if necessary. While this skill should already be familiar to riflemen, the recoil profile of pistols imparts additional information. Front sight movement immediately post trigger break shows whether it (and hence, point of impact) was moved by the finger. This author experienced front sight lateral offset and dip during class. With diligent analysis, he was able to diagnose his trigger pushing and flinching. This information afforded corrections during a course of fire to speed up the learning loop.

Continuous Improvement

Continuous learning and self-improvement through competition and instructor development forms a large part of Langdon’s shooting philosophy. Competition drives innovation and provides inspiration for improvement. Instructor development not only hones analytic skills, but it also improves the community by stocking the pond with good ambassadors. Langdon observed that students already take part in some form by simply trying to “one-up” their friends or taking someone to a shooting range. He encouraged the continual pursuit of such opportunities.

In fact, Langdon encouraged his students to attend classes from different instructors as different renditions of similar information can trigger “lightbulb moments” for different students. His personable nature and freewheeling Q&A on varying topics help students to connect with the material. In a sense, this approach is Kaizen applied to the shooting discipline.

Subconscious Performance

Langdon emphasized that one should train and “build muscle memory” until basic functions like pistol presentation and trigger roll can be performed subconsciously. Under stress (whether life-threatening or competition), the conscious mind is overwhelmed with processes such as discerning targets, relocating to cover and maintaining situational awareness. To draw a real-time computing analogy, these high-priority tasks occupy so many clock cycles of a frame that low-level functions get little or no execution time. When shooting the X-Drill, this author experienced “CPU overload” on the high-priority task of which box to engage next. To the detriment of marksmanship, there was no time to consciously implement the recently learned grip correction.

Stance

To better absorb recoil in static shooting, Langdon advocated a modified isosceles stance, where the elbows are not locked in full extension. For head and shoulder positions, he preferred a slight tuck of the neck—similar to how one would instinctively protect it when startled. However, he noted an over-aggressive “tactical turtle” may lead to discomfort and long-term health detriment.

Langdon also articulated various reasons to slightly cant the pistol. When firing with weak hand only, canting aligns the sights with the dominant eye without undue lateral shift of the arm. When turning the upper body to address a target on the strong side, lifting the strong side’s elbow can allow additional rotational movement. This cants the pistol as a side effect.

Optimal feet placement, on the other hand, was not overly emphasized due to the compressed timeline and propensity for movement during a defense scenario. Were a situation allowing a static stance to come along, students were taught to slightly stagger their feet (closer to fully squared than Weaver) in an aggressive forward lean while maintaining their weight on the balls of the feet. This affords better recoil control and facilitates movement.

Grip

For optimum recoil management, Langdon advised that the pistol beavertail be centered as high as possible on the natural web of the hand. He then explained the importance of maximum skin contact with aggressive grip material to gain traction and manage recoil. The stock plastic grips on the author’s pistol were worn too smooth for good purchase. Aftermarket G10 grips were found to offer improvements; however, it was noted that the golf ball dimple texture irritated the hand, while standard chequering proved insufficiently tactile. The Langdon Tactical Technology exclusive VZ G10 grips provided an optimal balance between hand comfort and grip. The texturing extends high to support a thumbs-forward grip, while the vertically elongated diamond chequering provides substantial recoil resistance without the irritation.

As someone who learned through internet discussion boards and videos, the author very much appreciated the discourse on the rationale for a thumbs-forward grip. Langdon explained that the grip is not about thumb placement but about palm contact with the pistol. Starting with a high strong-hand grip, the thumb is moved out of the way to open up a large area for support-hand contact. The support hand is then rotated down so that the wrists come together with no gap in between for maximum contact. For the author, this positions the strong hand’s abductor pollicis brevis muscle against the support hand’s thenar crease. This downturn of the wrist also preloads it for better recoil management.

To further explain the grip, Langdon drew an analogy between resisting recoil and pushing a table. It is more efficient to push against the table ledge in comparison with placing one’s hands on the tabletop to push via friction. Similarly, it is more efficient to catch the backstrap with the support hand instead of resisting recoil through grip panel friction alone. Specific to the Beretta 92 series, Langdon explained that the backstrap hump of the 92FS/M9 cleared the strong hand away for more support-hand contact, while the smaller grip of the Vertec model allowed less contact for most shooters. The 1.8-meter-tall author, after grip adjustments by Langdon, found that the 92FS/M9 was very comfortable and permitted an effective support-hand grip. To confirm good posture during practice, Langdon advocated firing at least two rounds after re-establishing grip (as in a reload drill). This is a corollary to how a low-recoil 5.56x45mm rifle hides bad posture even during the rapid-fire stages of high-power rifle competition, while a 30-caliber rifle breaks down and reveals poorly built positions.

Langdon also highlighted grip strength as the common thread between accomplished pistoleers (whether bullseye or International Practical Shooting Confederation), as it enhances recoil management and encourages consistent groups. Embracing the analytic approach, the southpaw author observed his front sight shifting right under recoil which required a manual reset after every shot. Reasoning pointed to a weak support-hand grip, as recoil naturally follows the path of least resistance. Assiduous application of full grip strength on both hands cured this problem.

During the two-day course, the author discovered his office-worker hands to lack in raw strength and stamina. Langdon suggested hand gripper exercise tools, reverse curls and even wringing out a wet towel. Using the fingers to gather a piece of paper into the palm and then ball it up also promotes finger dexterity, with reverse stretches recommended to maintain muscle health.

Trigger

Langdon is an advocate of the Double-Action/Single-Action (DA/SA) semi-automatic pistol.² To quickly and accurately deploy the DA first shot, Langdon advised performing a smooth trigger “roll” as part of the pistol presentation. When extending the pistol, one should keep the front sight slightly proud of the rear in order to better see and steer out lateral errors. Start rolling the trigger at the end of the presentation while obtaining the sight picture. The trigger should ideally break just as the proper sight alignment and sight picture are obtained, but by no means should one break the shot just because the pistol is fully presented.

Quickly pushing out the pistol can cause a “whipping” sight picture that requires time to dampen, while rapidly “slogging through” the trigger affords precious little time for proper trigger control. In order to better illustrate the benefits of combining trigger roll and presentation, Langdon used a shot timer to demonstrate both methods. While the combined deliberate motions seemed slower, it was actually about one-tenth of a second faster. After some practice, the author recognized how Langdon’s method allowed him to “take his time in a hurry.”

In teaching the optimal trigger break for self-defense, Langdon eschewed the traditional wisdom of “ever-increasing pressure with a surprise break” and opted for “slapping the trigger without disturbing the sights” instead. Given that target and own-ship motions are inherent to a defense scenario, it is nigh on impossible to maintain proper sight alignment and sight picture while applying ever-increasing pressure for a surprise trigger break. Instead, one must “slap the trigger without disturbing the sights.”

To do so, Langdon instructed the author to critically observe his own dry fire in order to discover the proper trigger finger placement to make the pulling movement effective. On command (from an assistant or a timer set on random), he broke the SA trigger promptly without a thought to ever-increasing pressure while observing any front sight movement. For the southpaw author, such movement to the right required the trigger finger to reach deeper onto the trigger face. Discovery of this proper placement, combined with a proper grip, vastly improved marksmanship.

Peculiar to DA/SA pistols are the two different trigger break points, but Langdon remarked that there was no need to shift finger position if they were close enough together. He further opined that Beretta does the best job of closing that gap in his experience. The author can anecdotally report that the difference between DA and SA break point was not discernible on his Beretta 92, and it was not necessary to shift finger placement.

Cover and Movement

Working with and from cover is a necessary skill, and Langdon imparted some wisdom for the responsible citizen who would probably respond to the threat alone. He mentioned that one should not tuck up overly close to cover, as it limits situational awareness, prevents full pistol presentation and increases exposure to ricochets. In order to lean left around corners in the most stable manner, one should lead with the left foot when standing. When kneeling to the left, place the left knee down to avoid contact between the elbow and knee at aggressive angles. Note that this is different than a team environment, where two people peek around the corner together (one standing and one kneeling), so the kneeler must place his left knee up to create space for his teammate behind.

While the class was focused on aspects of shooting, Langdon did provide tactics tidbits when applicable. He cautioned that part of one’s body is always exposed before the threat is sighted, because the eyes are not at the scalp or other extremities. While slow and cautious have their place, aggressiveness and commitment are sometimes warranted to reduce the time between exposure and response.

To demonstrate the importance of movement during a self-defense scenario, Langdon presented a Tueller-inspired drill while holding ground versus moving sideways. Movement created additional space and afforded the defender time to draw and shoot. Additional wisdoms include the fact that people are predominantly right-handed and are therefore more likely to miss leftwards when slapping the trigger, so it might be advantageous for the defender to move right (as viewed by attacker).

As for the mechanics of shooting on the move, Langdon advised students to squat somewhat in order to isolate the upper body from the impact of footsteps. To further reduce the shock, one should “roll” the feet to create smooth and continuous motions. Lastly, Langdon reminded students to incorporate movement into their draw practice to better prepare themselves.

Final Thoughts

The outline presented in this article does not do Langdon’s Tactical Pistol Skills class justice, as it merely reflects parts the author gleaned and not the entirety of the class. Langdon not only taught pistol skills (gave this man a fish), he instilled a philosophy of continuous improvement through critical analysis (taught this man to fish). The championship-winning techniques, concise delivery and masterful pedagogy make Langdon’s class well worth the price.

1. Langdon Tactical: langdontactical.com/about/
2. Ernest Langdon, “Why Choose a Traditional Double Action Gun?” YouTube, April 11, 2018: youtube.com/watch?v=m42IJIreRoc

Hearing protection is of paramount importance, since lost hearing cannot be recovered. Typical gunfire measures 150 to 160 decibels, with 140 decibels being the commonly accepted threshold for hearing damage. Cost-effective and readily available foam earplugs provide some attenuation, but that alone may be insufficient (Ylikoski et al., 1995). In addition, environmental factors such as an overhead awning or a barricade can cause reverberations and amplify noise to unsafe levels.

Impetus

The author experienced the amplification effect during a sporting event, when he fired through a tube with his 7.62x51mm rifle and head inside. Despite having tightly fitting foam earplugs, one shot dazed the author and caused temporary deafness in one ear. Other shooters with 5.56x45mm rifles also reported discomfort and disorientation, despite having their heads outside the tube.

This experience prompted the author to seek more robust hearing protection. “Doubling up” with foam plugs and a passive headset helped dramatically, but it also blocked conversations and range commands. MSA Supreme Pro-X electronic hearing protection overcame this by reproducing conversations while providing a passive noise reduction rating (NRR) of 18 decibels (Wonderling, 2015). This article examines both its passive noise protection and active ambient sound reproduction characteristics.

Fit

The MSA Supreme Pro-X is an ear cup design available with both headband and neckband options. The headband version places the band vertically over the head. Although one can wear baseball caps under the ear cups, this arrangement is incompatible with wide-brimmed hats. The neckband option places the main headband behind the skull and features an overhead net as an added measure to keep the ear cups in place. However, the cups still limit how tightly a hat can be worn, therefore chin straps may be necessary. The neckband option is also compatible with some helmets. The thin ear cups did not prevent the author from shouldering his rifles.

Ear cups come with standard foam cushions that can be upgraded to gel seals. Gel seals provide superior comfort and soundproofing, especially for bespectacled users. In addition, MSA offers a hygiene kit that replaces both the seal and the acoustic absorbent. Part number 10061294 replaces the standard foam cushions, while part number 10082377 replaces the gel seals. The head- or neckband cushion and overhead net can be removed for washing.

Electronic Controls

Three buttons on the left ear cup control the electronic sound reproduction. Tapping the middle power button turns on the electronics, while holding it turns them off with a long “beep.” If no buttons are pressed for four hours, the electronics emit a warning tone and automatically shut off. Pressing any button resets the four-hour timer. The “+” and “-” buttons control volume, with sound reproduction capped at 82 decibels to prevent hearing damage. The two highest volume settings amplify environmental sounds. A 3.5mm audio input jack is located at the rear of the left ear cup for use with radios, mobile phones, MP3 players or other devices.

Two forward-facing microphones, one on each ear cup, collect ambient noise for sound reproduction. Pro-X utilizes AAA batteries loaded in the right ear cup via a water-resistant cover.

Audio

The Supreme Pro-X works very well in conjunction with foam earplugs. At high volume settings, one can easily hear conversations and range commands through foam earplugs with little discernible delay. This allows for clear communication while maintaining a high degree of protection. It should be mentioned that, when a firearm is discharged 5 meters away under an awning, the Pro-X will reproduce the gunshot echo. This is notable even at the lowest volume setting. While a nuisance for range use, this serves as a testament to the sensitivity of the microphones.

The dual microphones offer credible stereo sound. One can easily discern direction from high off-boresight sources. The author felt oscillations in directionality with a source directly ahead reproduced at the highest volume setting. This effect is not noticeable when used in conjunction with foam earplugs.

The audio quality of the reproduced sound may not rival that of studio recordings, but it is quite good for everyday use. Voices are reproduced faithfully, so that different speakers can be identified by voice. When listening to the Trauermarsch of Mahler’s Fifth Symphony, the author noted a “scratchy” treble and the removal of bass elements, whether the music was electronically reproduced or played directly through the audio jack. However, this quibble is inconsequential given the primary role of the Pro-X for hearing protection.

Noise Reduction

MSA Pro-X is certified to an NRR of 18 decibels for the headband version and 19 decibels for the neckband version (Wonderling, 2015). This is comparable to foam earplugs (Ylikoski et al., 1995).

The author performed some rudimentary qualitative comparisons. Against the high-pitch noise of an electric leaf blower, the Pro-X seems as effective as foam earplugs, while “doubling up” provides further noticeable—but not significantly greater—attenuation. Against high-pressure gunshots, as achieved with .300 Winchester Magnum ammunition or a short-barrelled 5.56x45mm rifle, the author also felt that the thin ear cup design of the Pro-X did not attenuate as well as deep cup designs. Nonetheless, the Pro-X with foam earplug combination seemed to deliver markedly superior attenuation while facilitating a high degree of situational awareness.

The following plot shows attenuation with respect to frequency from the user manual.

Conclusion

MSA Pro-X offers an excellent combination of hearing protection and situational awareness. Environmental sound reproduction faithfully reconstructs the human voice and provides a good sense of source direction, even when used in conjunction with foam earplugs. The passive hearing protection provides an NRR of 18 decibels and combines with foam earplugs to give superior protection. The Pro-X is an excellent investment to protect hearing, especially for the author who enjoys his Shostakovich as much as his rifles.

References

Wonderling, J. (2015, July 6). “MSA Declaration of Conformity in Accordance with ANSI/ISEA 125-2014 IAC-09-014-ANSI-Z04_r1.” Cranberry Township, PA: MSA. Retrieved from http://s7d9.scene7.com/is/content/minesafetyappliances/IAC-09-014-Z04-ANSI_CAL_r1

Ylikoski, M., Pekkarinen, J.O., Starck, J.P., Pääkkönen, R.J., & Ylikoski, J.S. (1995). “Physical characteristics of gunfire impulse noise and its attenuation by hearing protectors.” Scandinavian Audiology, 24(1), 3–11. https://doi.org/10.3109?/01050399509042203

Having a compact, inexpensive and adaptable long gun in the vehicle to supplement a CCW handgun can be beneficial for fending off predators attacking live stock or fighting in the zombie apocalypse. This article investigates the ubiquitous pump shotguns for such roles. In the American West, pioneers would carry either a rifle or shotgun in a horse scabbard in addition to a pistol on their persons for hunting or defense. Rural citizens today still have the same requirements although their steeds now feed on petrol instead of fodder.

In the urban setting, and given the civil unrests in recent memory, citizens may wish to supplement their CCW handguns in the same way that police officers supplement their service handguns with patrol shotguns and carbines. To fill this role, the author set out looking for an inexpensive firearm not only because vehicular theft is an all-too-common occurrence, but because not everyone wishes to spend top dollar on a contingency item. As it had been for centuries, the shotgun fits this requirement well.

The Shotgun

We found a surplus Remington 870 Police Magnum for the modest sum of $250 including shipping and FFL fees.

Many classics such as the Ithaca 37, the Winchester Model 12 and the Mossberg 500 have languished on gun store shelves for reasonable prices.

It is worth mentioning that the Police model of the 870 has some differences from the Express model. The Police model features a longer magazine spring, heavier sear spring and heavier carrier spring. The trigger housing of the Police model is made of metal instead of plastic, and its extractor is machined metal instead of the metal-injection-molding of the Express. In addition, the Police model utilizes a ball detent on the barrel to lock the magazine cap whereas the Express locks against a serrated magazine spring retainer. Lastly, the Police model will accept a magazine extension without modification. The reader should weigh these differences when purchasing an 870.

The hard synthetic stock on the author’s 870 measures about 13.5 inches length of pull (LOP, measured from the recoil pad to the trigger) which fits the 5-feet, 10-inches tall author when using the bladed stance. However, it felt long when using the squared-up stance currently favored in action shooting sports. In addition, the comb was high enough to cause a 70% high pattern.

In order to address the ergonomic shortcomings, as well as to make the firearm more compact, we investigated four different stocks: Hogue short LOP stock (traditional style), Mesa Tactical Urbino stock (fixed stock with pistol grip), ATI Shotforce stock (top-folding) and Choate Telescoping and Side-Folding stock.

Hogue Overmolded Stock

The Hogue Overmolded stock comes in standard (Item# 08710) or 12-inch length of pull (Item# 08730). The short version is discussed below. The grip area is textured and made of a rubber-like material that promotes comfort and secure purchase. A forend (Item# 08701) with the same material is available as well to replace the standard, hard plastic forend.

The Hogue recoil pad is flexible but not tacky. The pad features slits that close completely around the attachment screw head to keep out lint and debris. To locate the slits, the user should compress the pad lengthwise.

The short LOP stock imparted the strength of a solid stock but kept the form factor compact at a 36-inch overall length for good maneuverability and easy storage. The shorter stock worked well with the squared stance for a small-statured tester where she or he can better reach the forend and cycle the action with authority. However, this tall author found the LOP too short for comfortable use. The shortness also made it difficult to pull the shotgun into the body and led to less effective recoil management. Lastly, the shorter length of pull placed the face closer to the receiver. This placed the eye higher over the barrel and resulted in a higher pattern. The Hogue Overmolded stock is comfortable and worked well for small-statured testers. However, the compactness did not outweigh the comfort of a longer stock for the taller author.

Mesa Tactical Urbino Stock

The Mesa Tactical Urbino stock is slightly longer at 12.5-inch LOP, but the pistol grip being much closer to the receiver made the stock feel longer for the author. The higher amount of drop at comb afforded a good sight picture. A cheek-riser, requiring a rail on the stock, is available to accommodate optics. Note that stocks with rails (e.g., SKU 91550) can be used without the riser, but the stocks without the rails (e.g., SKU 91540) cannot be equipped with the riser.

The pistol grip has a distinctive feel because of the square backstrap and 1.25-inch wide girth. Its design ameliorated felt recoil and reduced fatigue. The design prevented recoil from concentrating into the web and instead spread it over the “meaty” part of the hand between the thumb and index finger. The Santoprene beavertail promoted a high grip for better control as well as softened the recoil. The author found the pad of his finger to naturally rest on the trigger face, facilitating an accurate shot. However, the grip shape slightly complicated the trigger group removal from the receiver. In contrast to a traditional semi-grip, a pistol grip prevents the hand from jarring loose and hitting the trigger guard under heavy recoil.

The Urbino stock is available with a standard recoil pad or a Limbsaver model that admirably tamed recoil. The stock also features a wealth of sling-mount options. The bottom of the stock has a traditional swivel attachment. Halfway between the recoil pad and the grip is an attachment point that allows for a US standard 1¼-inch sling on either side or that can be left off to reduce clutter. The last attachment option is at the front of the stock where the user can either thread a sling through, use an HK-style clasp, or not have a mount at all.

The feature-packed and ergonomic Mesa Tactical Urbino stock has a chief drawback of size. Although the length of pull is relatively short, the increased drop at toe and heel in addition to the pistol grip means the shotgun requires more vertical space. The next two sections investigate folding stocks for that issue.

ATI Shotforce Top-Folding Stock

The ATI Shotforce stock (Part# TFS0600) is similar to the Remington factory steel top-folding stock, but it is made of polymer. To deploy, the user depresses the button on the left side and rotates stock down.

It is locked when the button latches into a cutout. The buttpad is then rotated perpendicular and retained by friction. The buttpad is checkered for grip and does not have any recoil absorption. The slight play when deployed does not impede firearm sighting or function.

The length of pull is slightly longer than the standard field stock and stretches the arm out further because the pistol grip is closer to the receiver than the traditional grip. The author also found it difficult to achieve a proper sight picture due to the thickness of the stock. A higher sight plane is necessary with the stock, but the optics interfere with the folding. The ATI Delux Heatshield with ghost ring sights (Part# SBS4600) provides the proper sight picture without interference. Five additional shells can be secured with the Shotforce Shell Holder (Part# SHO0500).

The ATI stock significantly shrinks the firearm footprint without adding much weight. However, it is not quick to deploy and is perhaps best used where compactness and weight are prized, but accurate shot placement at distance is not an overriding priority.

Choate M4 Telescoping/Side-Folding Stock

The Choate stock features side-folding and telescoping abilities. The bracket is made of steel and is notably heavier. It folds to the right and does not interfere with firearm operation because the slight drop at heel moves the stock out of the shell ejection pattern. To unfold, the hinge is pushed down against spring pressure to unlock the two lugs, and the stock is swung around until it solidly locks open with no play.

The stock has two storage tubes like that found on SOPMOD AR-15 stocks; and while the hard rubber buttpad provides a firm grip on the shoulder, it does not tame the recoil. The pistol grip is made of a hard plastic, checkered for a sure grip, and features a non-removable sling loop at the bottom. In addition, there are other attachment points on the hinge and two more on the stock. The stock features a slight drop at heel but still places the head too high for the bead sight. It reduced the footprint, but the solid construction came at the expense of increased weight.

Shell Holder and Magazine Extension

Use cases for the trunk gun are generally of the “grab-and-go” type where the threat is addressed with the ammunition already on the firearm. There are two easy ways to increase the supply: the shell holder and magazine extension.

The TacStar six-shell, side saddle has an aluminum backing plate that attaches to the receiver via the trigger group pins. If the pump were cycled with the left hand too far rearward, it may painfully contact the backing plate. The holder can carry more shells than a typical two-shot magazine extension; it also offers flexibility by allowing slug changeovers. However, the holder nearly doubles the width, and the extra shells must first be inserted before being used.

A magazine extension typically increases shell capacity by two if flush with an 18-inch barrel. The Choate extension (product# 01-04-02) is made of steel and replaces the original magazine cap. The base clamp is attached near the muzzle, providing a sling attachment and preventing damage in case of impact. The magazine extension provides extra ready-use ammunition at the cost of flexibility, and the extra weight at the muzzle can more easily induce fatigue.

Shooting Impressions

A shotgun is violent on both ends. The user can manage recoil by applying forward pressure on the pump while pulling the stock into the shoulder. Even so, the muzzle rise is more notable than that of a .30-caliber rifle.

The author patterned the improved cylinder barrel with PMC low velocity 1200 fps, nine pellets, 00 buckshot against an 8.5×11-inch sheet of paper that roughly approximated the vital parts of a human torso. At 7 yards, all nine pellets landed within 6 inches. Past that distance, not all pellets landed on paper; the results are summarized below.

Fiocchi 1-ounce, 1150 fps Exacta Aero Slugs were also tested for accuracy. At 50 yards off-hand, the author was able to place five slugs into an 8-inch group.

The 1-ounce Fiocchi slug had notably less recoil than that of the PMC buckshot which weighs about 1.2 ounces. Indeed, the buckshot recoil caused the southpaw author’s trigger finger to slam into the aluminum shell holder backing plate when using a pistol-gripped stock. However, right-handed testers did not report similar problems. This difficulty did not arise with the traditional stock because of the different grip angle.

Conclusion

The pump shotgun makes the inexpensive and effective trunk monkey able to supplement a pistol. Its close-range power is undeniable, and its ability to deliver different payloads gives it versatility for differing situations. However, the typical shotgun has low-shell capacity and is not overly compact.

This article explored some options in making the shotgun more compact and ergonomic. Short length of pull stocks are good at reducing length and maintaining rigidity but being too short can be detrimental to ergonomics. A pistol grip provides more control in both handling and recoil but comes at the cost of a larger vertical footprint. Folding stocks are excellent in promoting compactness, but the loss in rigidity with plastic construction can only be addressed with heavy steel.

The low-ammunition capacity can be addressed by shell holders or magazine extensions. The former add flexibility in carrying different shells ready for a change-over and carries more ammunition, albeit not in the magazine. The latter increase the ready-use capacity but add weight at the muzzle, which can induce fatigue.

However configured, having a shotgun trunk monkey is a cheap and effective insurance against aggressive predators, the next LA riots or the dawn of the dead.

By Alton P. Chiu

Avtomat Kalashnikov, a storied and proven rifle, is adored by both militaries and citizens alike. However, its propensity for vigorous cycling and ejection can cause complications with sound suppressors as well as induce premature wear and tear even when unsuppressed. The KNS adjustable gas piston mitigates this overgassed condition that factory rifles commonly arrive with.

Principle of Operation

Unlike an AR-15 gas block, the AK’s is interference-fitted to the barrel and requires a shop press to remove. Although aftermarket adjustable gas blocks exist, they cannot be easily installed at home. The KNS adjustable gas piston changed that as it only requires one to field-strip the rifle; installation can be accomplished by hand tools. No permanent modification is necessary, so there are no qualms partnering it with a collectable parts kit.

A hole at the tip of the KNS piston channels excess gas to a vent further back on the piston, whereby it makes its way out of the gas tube. The size of the piston vent hole is regulated by a collar in order to soften the recoil impulse and facilitate controllable rapid fire. The collar moves axially along the piston by threading around it like a nut.

KNS produces variants with different thread pitches, hole distances and working lengths to fit the AK family (including but not limited to AKM, Arsenal, Yugo, Krinkov) and even its extended cousins (e.g., Valmet, Galil). For this article, the AGP-A-20S model was evaluated on an Arsenal SLR106F chambered in 5.56x45mm which sported a 16-inch barrel.

Installation

The rifle was field stripped and the bolt carrier, sans bolt, was removed to a vise. Note that the bolt carrier is hollow, and the vise jaws should be applied to the piston to avoid damage. The author then searched for the rivet securing piston to carrier with a good light source in order to remove the OEM piston. During installation at the factory, a rivet was bucked on both sides into the countersunk holes on the carrier. The excess material was then ground down and finish applied over. The one on the Arsenal ran side-to-side and was fairly well hidden. The author prepared the rivet for drilling by first creating a divot with a center-punch. A 5/64-inch drill bit was applied about 2mm deep before the punch and hammer were used in earnest to drive out the factory rivet. The OEM piston could then be unthreaded from the carrier.

The KNS piston came pre-drilled in two axis so that a hole is visible with every quarter turn. The piston was then threaded into the carrier until the holes were aligned and the roll pin inserted. This pre-drilling saves the end user from needing a drill press as in the traditional assembly process. As with the factory counterpart, there was some wiggle in the KNS piston to carrier fit which did not impede function.

The author found the installation procedure quick and easy, requiring only a standard hand tool he already owned. However, KNS also offers an installation service with same-day turnaround for a small fee.

Shooting Test: Methodology

Since the test rifle is chambered in 5.56x45mm with a 1:7 twist barrel, the author used five different ammunition loads (in both 5.56 and .223 pressures) as the treatments. Changes in group size, point-of-impact and felt recoil (measured qualitatively) form the response variables.

Federal XM193 55gr and XM855 62gr represented the 5.56 pressured ammunition. Wolf Polyformance 62gr HP and 55gr FMJ provided data for .223 pressured ammunition. Lastly, the author’s handload for across-the-course high power matches (75gr Hornady HPBT, 24gr Ramshot TAC, CCI #41, LC case) provided a data point in between the two pressures.

To reduce the atmospheric effects, targets were placed 25m distant. To reduce the effects of a heated chamber, five shot strings followed by a 3-minute cool down period were observed. To reduce bias from factors such as shooter fatigue and lighting variations throughout the test session, a random treatment (i.e., ammunition) was drawn for each five shot string with no repeats allowed. The strings were repeated until 10 shots were fired for each treatment. To avoid swapping pistons repeatedly, the author first collected factory piston data in one session with KNS piston data collected later. The sights were not adjusted during testing, and a 6 o’clock hold was used on a 4cmx4cm square.

Shooting Test: Data and Discussion

Following KNS instructions, the author started with the collar fully closed and then opened five clicks at a time until short-stroking occurred. The collar was then closed two clicks at a time until reliable cycling was achieved. Wolf Polyformance 55gr FMJ had one out of 10 failure-to-cycle with the OEM piston, but it adamantly refused to cycle even with the KNS piston collar fully closed. Wolf Polyformance 62gr HP had four out of 10 failures-to-cycle with the OEM piston and also wholeheartedly declined to cycle a fully closed KNS piston. While their muzzle velocity data are included in this article for completeness, they are considered “no-tests” and not further analysed. Note that this is not an indictment on the ammunition, rifle, or piston; it merely illustrates the challenge in achieving reliability across numerous variables.

Using the OEM piston, the empty brass of XM193, XM855 and 75gr handload all exhibited dents from impacting the dust cover and were flung to a 2 o’clock position 15 feet away. The excess gas also drove the rifle off-target with every shot. Using the KNS piston, XM193 cycled reliably with the collar 13 clicks open, XM855 11 clicks open and 75gr handload five clicks open. As adjusted, none of the brass exhibited dents. XM193 and 75gr handload deposited brass at 3 o’clock four feet away while XM855 ejected brass at 4 o’clock 10 feet distant. All three ammunition types cycled notably softer with the rifle staying on target. As the tabulated data shows, there was no discernible difference in muzzle velocity between the OEM and KNS pistons.

On the other hand, plots of the shot groups show a shift in point-of-impact but not in group size. While not statistically significant, the shift does illustrate an interesting trend. 75gr handload shows a marginally decreased group size (0.2 MRAD) with the KNS piston as well as a sizeable lateral shift of the group center (0.9 MRAD). XM855 exhibited a nearly identical group size and marginal lateral shift of the group center. XM193 displayed no change in group size and a diagonal up-and-right shift in group center. While providing a reason would be pure conjecture, it is reasonable to expect needing a re-zero after installing the KNS piston.

Also, note the horizontal pattern of the 75gr handload compared to the predominantly vertical pattern of the XM855 and the circular pattern of the XM193. It is reassuring that changing the piston did not visibly affect the way the rifle patterns.

Conclusion

The KNS adjustable AK gas piston is a worthwhile addition for mitigating the overgassed condition that factory rifles commonly suffer from. It notably reduced recoil and muzzle jump while the resulting slower bolt speed should increase parts life. Indeed, this piston may help a shooter win so much that one gets tired of winning.