K-VAR Corporation :: AK-74 Muzzle Brakes/Compensator

AK-74 Muzzle Brakes/Compensator

AK-74 Muzzle Brakes/Compensator

Arsenal Inc. and K-VAR Corp.

in conjunction with the Kalashnikov Collectors Association USA


'Collector's Corner' -an online journal for the Kalashnikov enthusiast

Edition № 1:
AK-74 Muzzle Brakes/Compensators

Mystery has always been a part of the venerable Kalashnikov rifle's mystique and draw; a certain 'unknown' factor that fascinates collectors, historians and shooters alike. The AK rifle, being a widely produced weapon, and having so many facets of technical and historical merit, seems to captivate anyone involved in the arena of firearms. This online journal series intends to 'feed the fire' of the Kalashnikov fanatic, and hopefully reveal some of the mysteries surrounding the AK weapons system. I would like to thank Arsenal Inc. and K-VAR Corp of Las Vegas, NV for the opportunity to spread some of the knowledge that we at the Kalashnikov Collectors Association have spent so much time researching and archiving over the years. The KCA is a research and enthusiast group founded in 1999 that is working to be the 'go-to' source for Kalashnikov related information for government personnel, law enforcement, military and historians alike. We hope you enjoy this edition of the 'Collectors Corner'!

-Joe Ancona
President & Founder of the Kalashnikov Collectors Association

This edition of 'Collector's Corner' focuses on one of the most interesting and conspicuous components of the AK-74 rifle system, the muzzle brake device, or compensator. As most of our readers know, when we refer to the AK-74 and its variants, we are referring to the Kalashnikov rifles that are based on the 5.45x39.5mm M74 high velocity/small caliber bullet, introduced in the mid 1970's. The older .30 caliber AK-47 and AKM rifles either did not have any muzzle devices, or had a more simplistic affixment, which we will not discuss in the scope of this article. It is interesting to note however, that most muzzle attachments serve multiple purposes, whether it be a combination of flash suppression, sound reduction, recoil abatement, gas pressure regulation, enhancement of bullet exit dynamics, blank firing capability, or simply being a mounting point for other accouterment (such as a bayonet).

Since the introduction of the Soviet AK-74 brake, there have been dozens of variations on the theme that span many years; with regard to different countries and calibers alike. In the arena of today's Kalashnikov rifles systems, either military or civilian, it is an implicit sin to have a bare muzzle, or one with only a thread protector! For a collector however, the priority in muzzle device selection lies with the correctness of the build, not so much with the trend of the day. Regardless, in the past 10 years or so, we have seen a large increase in demand for AK rifle accessories, and I am sure that the muzzle devices are near the top of that list for desirability. They are easy to install, provide a function, and give immediate impact to the visual appearance of the overall package. It is one of those instant gratification 'add-ons' for sure.

If you are a shooting enthusiast, there has always been a good array of do-dads to screw onto the end of your favorite AK. For the collector and builder of historically accurate Kalashnikovs however, the choices have been next to non-existent; many builds having to make do with incorrect designs or inferior replicas. How does one determine what is correct or what is not for a particular model of AK-74? Well, that is where our KCA group has the most enjoyment, in researching the production variation within the Kalashnikov lineage, for our own interests and (hopefully) for the benefit for others.

For this volume, I have entrusted a couple of our own AK mavens who specialize in the AK-74's Soviet development to bring you the 'ins' and 'outs' of the Russian produced muzzle brakes. Please let me introduce to you, Douglas Ford and Michael Eklund, more commonly known via their 'call signs' Tantal and Ekie. Like Doug and Mike, I tend to focus on the Russian engineering, design and production of AK sub-components. Of course, there are dozens of other countries who adopted the Kalashnikov and made their own modifications to the design. In general however, it is most helpful to study the parts as made by Russia, and follow the trickle down technology from there. In this respect, most of what you read and see in this series will be specific to Soviet Russian patterns. As you can imagine, the Soviet Russians dictated the progress and specifications for this rifle system for all of the countries licensed to produce it (within the bounds of the time frame we are discussing, approximately 1949 to 1991). In future articles, I am certain that post-Soviet guns will be a subject of discussion since the evolution of the AK continues in full force today, and will continue to do so..... as long as there are people on this earth, and bullets to be had!

The following data, text and photos have been compiled and kindly provided by Tantal and Ekie, and are a part of their ongoing dedication to the historical preservation and technical cataloging of the Kalashnikov rifle, as seen on the Tantal's Collectors Source web site, which has been active for over 10 years.

1: "Half Moon" One-Piece

Found on pre-production until late 1979 (or early 1980) rifles

Description: One-piece construction, carefully machined with fine mill lines front to back. Large forward side ports have an inverted-v shaped cross-section, and feature a thin upper bridge and a wide, flat lower bridge. The deflector plate on the front of the port has a thin side profile with sharp edges, and a relatively short bayonet ring extension. While preproduction rifles had an elongated threaded collar, production brakes have a shorter collar similar to the later zigzag, usually beveled at the rear almost exactly halfway down the length of the threaded collar. The distinctive features which gave this brake its popular name were the semi-circular or crescent-shaped blast deflector cuts milled into the forward face of the expansion chamber on either side. Because this brake has a shorter bayonet ring attachment journal extension, this makes it slightly shorter in overall length than any other Soviet AK-74 muzzle brake. This specific brake was not copied by any other country to our knowledge (with the exception of the US, see end of article), and therefore remains quite rare.

(photo: J. Ancona)

(photo: J. Ancona)

(photo: M. Eklund)

Author trying to capture some shots of the rare 'Half Moon' brake in a Moscow museum, 2003 (photo: R. Stepanov)

Even in the first American encounters with the AK-74 in the early 80's, the efficacy of the AK-74 brake was immediately evident.

(Photo: Soldier Of Fortune Magazine)

2: "Zig-Zag" One-Piece

(photo: D. Ford)

Found on mid-1979 until 1982 (or early 1983) rifles

Description: One-piece construction as before, with the short length threaded collar. However, the beveled taper at the rear edge is much shorter in length, starting closer to the rear edge of the brake. The thin forward deflector bridges (with the port mill-cut in an inverted V-shape) and sharp tapered forward deflector are both retained, but the face of the expansion chamber does away with the early crescent-shaped gas vents and now exhibits the so-called "zig-zag laser cuts" which give the brake its name. The attachment extension for the bayonet has been lengthened, giving the brake an overall longer length. This muzzle attachment was imported to and eventually copied by both East Germany and Bulgaria.

(photo: C. Mayer)

Close-up of the characteristic "zig-zag" gas vents and inverted v-shaped forward port design (photo: C. Mayer)

(photo: M. Eklund)

3: Two-Piece "Smooth Collar" (facet-pattern)

(photo: S. Hood) Found on 1983-1989 rifles, with evolutionary modifications.

Description: Two-piece construction. The forward face of the expansion chamber is fabricated using a separate bullet baffle plate, which is pressed into the forward walls of the muzzle brake expansion chamber and peened into place. Unlike early designs (which had integral bullet baffles), the new two-piece brake has thick bridges and a forward port with cylindrical rather that flat surfaces. Texture and collar length can greatly vary on this design, but most exhibit very distinctive "hammer forged" facets or "arrowhead" textures usually laid out in a spiral pattern along the circumference of the expansion chamber. It is very difficult to identify sub-types in photographs, however all examples have a moderately short threaded collar and display a very smoothly flowing side profile due to the forward transitional step of the threaded collar actually being made from three shallow angles. As time went on, the fletched or scalloped appearance slowly became more smoothly finished and are sometimes hard to see (unless the painted finish has worn off). This exact design was never adopted in whole by any other country, and has therefore remained rare.

The two-piece manufacturing method was copied by Bulgaria, and most of the AK-74 two piece short collar brakes found in the US are of Bulgarian origin. The Bulgarians decided to simplify production and did not adopt the rather idiosyncratic fletched look of the Soviet models. It therefore kept the traditional stepped collar of the early zig-zag brakes. However, the thicker forward cylindrical interior section of the Bulgarian bridge section is basically identical to the Soviet two-piece brakes.

3B: Modified Two-Piece (smoothly finished pattern)

(photo: D. Ford) Late 1980's production, the smoothly finished short collar two-piece variant

Description: These late 1980's manufactured short collar brakes seem to be identical in basic design to the facetted version mentioned above. However, they have been finished in a smoother texture that looks similar in appearance to the modern two-piece brake shown below. The exact year (or years) these may have been used is still up for discussion, but some rifles in the 1988-89 period seem to show this brake. It has very subtle scallops along the threaded collar step (similar to the late AK-74M brake) and vague ridges along the entire cylindrical surface of the expansion chamber. There are both examples with a rear bevel cut, and some without, which is also the case with the later "AK-74M" type FSB shown below. This is not the case with any earlier style of AK-74 brakes (except possible some hyper early pre-production designs). All things considered, this brake seemingly fits into a time period right before the current style which it shares many similarities with. In most grainy and/or combat photos of AK-74 rifles, this brake would be hard to distinguish from other two-piece brakes.

(photo: M. Eklund)

4: Modern Extended Collar Two-Piece

(photo: D. Ford) Found from 1990-current production

Description: Relatively similar to the earlier smooth collar two piece, except that the threaded collar has been greatly lengthened to increase the strength of the bearing surface that contacts the front sight base. The collar is so long that the most rearward gas port on the expansion chamber (right hand side) is now located on the distinctively scalloped forward edge of the threaded collar. The longer collar matches the lengthened brake attachment extension on the new front sight bases of AK-74 and AK-74M rifles designed in the late 1980's and is retained even today. This model is often called the "AK-74M brake" and is also standard on the full-length rifle versions of the AK-100 "Century Series". Although never adopted by any other country for domestic production, US-made copies do exist from several sources.

(photo: M. Eklund)

Thank you again to Doug and Mike for providing such a rich resource in Kalashnikov manufacturing history. It takes years of research to determine production variation and time-lines, as there are very few sources for such esoteric data. Much information is first 'put to paper', then confirmed many years after its discovery, from first hand sources, books, photos, or simply process of elimination. This is what makes this type of research so interesting!

Now that we have seen an assortment of common, and not so common AK-74 breaks as produced by the former Soviet union, lets take a look a some offerings from K-VAR Corp. which faithfully re-create the Russian style brakes, but with a manufacturing process fit for the aviation industry. Below is the limited production (both in history and here from K-VAR!) early AK-74 style compensator, model number AK-143US. It is a nearly an exact re-production of the hard to find collectible known as the 'Half Moon' design, as referenced above by my KCA brethren. K-VAR also supplies an even more rare variant very similar to this one, that has a longer 'collar' that mimics the earliest AK-74 prototype guns circa 1973 (part AK-141US). These breaks are interesting because the actual gas 'slits' are only formed when the right amount of metal is removed to reveal them during the machining process. Other designs utilize EDM cuts, or a second inserted part (baffle) to create the vents. The 'Half Moon', being the earliest known Soviet production AK-74 break, is the most delicate and machining intensive way to produce the slots, and in my opinion, makes these the most interesting brakes in the AK-74 series.

Both of these USA made parts boast K-VAR's newest production capabilities, which are at a level that I have never seen before in the AK accessories world. Manufactured on a CNC turning center, concentricity throughout the part is guaranteed, and 100% repeatable. A very expensive 4340 high grade steel is used, to allow the implementation of a very sophisticated vacuum/IR radiant heat treat process, for perfect hardness. Cheaper 4140 steels are just not suitable for this type of computer controlled high-end bake job. With virtually zero distortion on every part produced, fit and function should never be an issue, and you get the proper looks to boot. Aside from the proper shape contours, note the chrome lined blast area and military grade external coating, just like the original. To show its USA origins, K-VAR has cleverly stamped the inside chrome face of the baffle, as not to scream 'impostor' to the collector's eye, yet giving the part full 922r compliance. The only fault that I can find, is that if anything, the part almost looks *too* good for communist bloc production lines. I can understand however, that with modern CNC machinery, programming in 'fake' machining marks would not only be time consuming, but almost sacrilegious to a highly evolved CNC machine designed for smooth cuts! Some machining marks do remain however, and this part should satisfy anyone looking to complete their early AK-74 build (from the collector's standpoint), as well as providing the sport shooter with the highest end AK-74 style muzzle device available.

-Joe Ancona

Author's early attempts to replicate the 'Half Moon' brake on CAD software, proving the design to be a very complex from a machinist's standpoint.

(photo/CAD: M. Mitchell)

K-VAR's AK-143US (photo: J. Ancona)

K-VAR's AK-141US (photo: J. Ancona)

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