I am researching the AN-94 and have come across several articles that have carefully reviewed this rifle.  The one item that interests me is the sonic brake component.  This is old technology but it seems to be very smart.  Has anyone seen these brakes on the market?  can you order one?  Is it legal?  Let me know what you think.

Here is an interesting article on the AN-94

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The next feature that grabs your attention as you're pawing it over is the rifle's muzzle attachment. Referred to as a flash eliminator, it's a significant departure from the brake utilized on the AK-74M, or anything else in the world for that matter. An asymmetrical design, it features two chambers with a port on either side at the muzzle. In addition, there is one strategically placed vent hole on the upper right of the first chamber. This is referred to as a "whistle," which Krebs took to indicate a sonic whistle.

A sonic whistle is very old technology, to the point of almost being forgotten. Similar in concept to a dog whistle, it alters the report to an ultrasonic pitch the human ear cannot detect. In the past, the Russians had problems with hearing loss from troops using the AK-74, so anything that can drop the weapons sound signature is appreciated. The unit removes easily by simply depressing a lever and turning it 90 degrees. Looking through it revealed no obvious voodoo. It doesn't surprise me that the Russians have moved away from the AK-74M style muzzlebrake. While effective as a brake, it does have the undesirable side effect of producing a huge muzzle flash in lowlight.
<snip>

Hmmm, interesting.  It does sound like it would just damage your hearing on a different level to me though.  

I've always wondered how any soldiers equipt with small bore assault rifles don't go deaf in short order.  I know you don't "hear" the sound as much when you are excited and adrenaline is going, but that doesn't change the actual damage itself.  

By the description is seem it would be a flash suppressor, and the ATF may also consider it a suppressor if it succedes in making it quieter.  

To hell with the break, I want the whole gun!! When I become President you will be able to buy them at Wal-Mart....LOL

Hmmm, interesting. It does sound like it would just damage your hearing on a different level to me though.

Yes but the concept of "super-sonic" convergence of a fired round would be like a dog whistle.  It would bring the report up to a level outside of the human hearing range.

I too thought this was really interesting when I read the mag article.  Hard to believe we can't find *someone* who can get a legit version from Russia for someone to reverse-engineer (and hopefully avoid any patents).

take care,
Tec

Found this article out on the web.  I remember discussing this weapon two years ago.  My biggest problem is nothing more than aesthetics...why in the hell did they design the pistol grip to appear to be "an after thought?"  It almost reminds me of one the post ban AKs with the angle cut rear receiver....just plain ugly.....

Anyway......






Caliber: 5.45x39 mm
Action: Gas operated, rotating bolt; moving barrel-receiver-gas drive group for delayed recoil action
Overall length: 943 mm (728 mm with butt folded)
Barrel length: 405 mm
Magazine capacity: 30 rounds
Weight, without magazine: 3.85 k g
Cyclic rate of fire:  1800 and 600 rounds per minute variable (see description below for explanation)
Maximum effective range: 700 meters

The AN-94 assault rifle had been officially adopted by the Russian Army and the Ministry of Internal Affairs in 1994 as a possible replacement for the venerable Kalashnikov AK-74 series assault rifles. The AN index means "Avtomat Nikonova", or Nikonov Assault rifle. This rifle had been designed by the Gennady Nikonov, a Russian arms designer, at the IZHMASH state factories, during the late 1980s and early 1990s. This rifle, initially known as the ASN prototype, had been developed for and submitted to the Russian Army trial contest, held in the early 1990s. This contest, known under the code name "Abakan" (a small city in Russia), was intended to develop the more effective replacement for the AK-74 assault rifles. The ASN was tested among the many other prototypes and eventually won the trials, and was consequently adopted. Originally it was intended to replace most, if not all, AK-74 rifles in the Russian service, but it soon turned out that the complete replacement is impossible due to the economical (mostly) and some other reasons. At the present time the AN-94 is considered as the "professionals' choice", and is used in limited numbers by the elite forces of the Russian Army, police and Internal Affairs Ministry. The main body of the Russian armed forces are still armed with the Kalashnikov assault rifles, and AK-type rifles will remain in service for a long time, most probably.

Much controversy is created about the AN-94 rifle, mostly because it is advertised as a quantum leap from the Kalashnikov designs, and because of its official action description, known as the "blow back shifted pulse (BBSP)". This weird description could confuse anybody, especially since it is used in conjunction with the note of gas operation of the AN-94. I will try to explain the operation of the AN-94 later in this article, but first I will discuss some of its main features.

The key improvement of the AN-94 over the AK-74 is the introduction of the 2-rounds burst mode, added to the standard single shots and full auto mode. The two rounds bursts are fired at very high rate of fire, and a trained shooter can make a single hole in the target at 100 meters in this mode. This allows for significant increase in lethality, stopping power and body armour penetration over the single shot mode, with the same "single shot" accuracy. The full auto mode of AN-94 consists of the two stages - first two rounds are fired in the "high rate" fire, and the remaining rounds are fired in low rate of fire, until the trigger is released or the magazine is emptied. In the single shots or the full auto mode, there's no significant advantages over the AK-74. At this point, one can ask "is all this complication of the AN-94 mechanism worth the achieved results"? From my point of view, there's no simple answer. The trained professional warrior can use the 2-rounds burst capability of AN-94 to the great degree of success, but prior to this, a lot of time and resources should be spent to train this professional soldier to use AN-94 effectively. Unlike the more common designs, like the Russian Kalashnikov or American M16 rifles and others, the AN-94 internals are not "user friendly", and it took weeks, if not months, to get used to this rifle, its assembly / disassembly and maintenance procedures. It is also more expensive to made and maintain, than the AK-74. From all this it is obvious why this very interesting rifle hardly will see any widespread service, at least with the Russian Army (which at this moment is conscripted by the large, and on a low budget). On the other hand, some elite units can make a good use for major advantages of the AN-94.

From the personal, but trustworthy reports I can add the following. First, the ergonomics of the AN-94 is not the best one. The shape of the pistol grip, and the inclined from the vertical plane magazine are way from being comfortable. The rear diopter sight has small apertures, not protected from dirt, and is hard to clean in the battle conditions. It also has sharp edges and can snag in the clothes or make a scratches on the skin when handled roughly. The grenade launcher mount under the barrel is a little weird, since it uses a large "bridge" between the stock and the launcher. The folding butt interferes with the trigger when folded, and the fire selector, which is separated from the safety, is hard to operate, especially when wet. On the other hand, as said above, in the 2-rounds burst it is very accurate and offers a great advantage in the terminal effectiveness over the standard single shot mode.

Part two of the article:

Technical description of the AN-94 assault rifle.

The heart of the AN-94 is the more or less common gas operated, rotating bolt, long piston stroke action. The barrel with the gas chamber above it is mounted on the receiver, which holds the reciprocating bolt carrier with relatively short rotating bolt. The receiver is allowed to recoil inside the plastic gun shell or housing, against the receiver recoil spring. This spring is located under the receiver, at the bottom of the housing and to the left, and because of this the magazine is offset and inclined from vertical to the right. The rod under the barrel, which looks like the gas tube, is, in fact, a forward guide for the recoiling barrel / receiver assembly. This rod also used as a forward mounting point for the grenade launcher. The cocking handle is attached directly to the right side of the bolt carrier.

The feed system is quite unconventional, since it had to transfer the rounds from stationary magazine and into the recoiling receiver. To achieve this, AN-94 uses a two-stage feed, that comprises a feedway, built into the bottom of the recoiling receiver, and a separate rammer, that is used to feed the cartridges from the magazine and into the feedway.

In brief, the AN-94 works as follows. First, let's assume that the full magazine is inserted and the chamber is empty, receiver / barrel assembly is in the forward position. When one pulls the charging handle, the bolt carrier goes back, unlocking and retracting the bolt. At the same time, the rammer, which is linked to the bolt carrier via the thin steel cable and a large pulley, goes forward, stripping the first round from the magazine and placing it into the feedway in the receiver. Another action that takes the place the same time is the cocking of the hammer, which is also located in the recoiling receiver. When the charging handle is released, the bolt assembly goes forward, slamming the cartridge from the feedway and into the chamber, and locks the barrel. Now, the gun is ready to fire.

When fire selector is placed to the "full auto" mode, and the trigger is pressed, following happens. As soon as the fired bullet passed the gas port, the traditional gas operated action begins. Since the bolt group is relatively light and the amount of the gas pressure is carefully calculated, the bolt group rapidly goes back, unlocking the barrel, extracting and ejecting the spent case. Due to the recoil impulse, the barrel receiver assembly begins to recoil inside the gun housing, compressing the recoil spring. At the same time, the cartridge rammer quickly strips the next cartridge from the magazine and introduces it into the feedway. The bolt group, under the influence of its main spring and the return buffer spring, rapidly goes forward, chambering the second round from the feedway. As soon as the bolt group locks the barrel, the hammer is released automatically, and the second shot is fired with the theoretical rate of fire of 1800 rounds per minute. At this moment the receiver is still recoiling inside the housing, and its recoil is accumulated and not yet affects the shooter and the position of the gun. When the second bullet is fired and left the barrel, the recoil cycle of the receiver / barrel group is stopped, and the hammer is held in the cocked position. At this moment the shooter feels the recoil of two fired rounds simultaneously, "shifted in time". The reloading cycle continued as described above, but the hammer is held until the recoiling unit will not be returned into the forward position. If the gun was set to the "2 rounds bursts" mode, the hammer will be held cocked until the trigger will be released and then pulled again. If the gun was set to the "burst mode", the hammer unit will switch itself automatically to the low rate of fire, and will release itself only once per complete recoil cycle. I will not describe the design and the action of the trigger system of the AN-94, since it is way too complicated to be explained in few words.

The further understanding of the AN-94 action can be (or at least I hope so :-) obtained from this link, which will display a small set of drawings and descriptions, extracted from the official patent, granted to the Nikonov and his team.

Other features of the AN-94 include: the fiberglass-reinforced polymer housing, integral with the handguards; the magazine bay that can accept standard AK-74-compatible magazines with 30 or 45 rounds capacity, as well as the newest 60-rounds four-stack box magazines. The sight system of the AN-94 is a step aside from all previous Russian assault rifles, and comprised by the protected front post, adjustable for zeroing, and the asterisk-shaped rear diopter, with 5 apertures drilled in the asterisk points. To set the distance, one must rotate the asterisk and set the desired aperture at the top of the receiver. The universal scope mounting rail is attached to the left side of the receiver as a standard. The safety and the fire selector are two separate controls. The safety is mounted inside the triggerguard, and the fire selector is a small switch above the triggerguard at the left side of the receiver. The fire selector has 3 positions, for single shots, 2-round bursts and for full-auto. Safety has 2 positions - Safe and Fire. The buttstock is made from the same high-impact plastic as the housing / stock unit and folds to the right to save the space. The strange-looking "8"-shaped muzzle attachment is a special, self-cleaning muzzle brake, which is claimed to be highly effective. It can be easily detached from the muzzle if required. The front sight base carries a rear bayonet lug on its right side, so the bayonet is mounted in the horizontal plane, to the right of the muzzle. This allows to fire the grenade launcher with the bayonet attached (which is impossible with the Kalashnikov-type rifles).

HUH?????

(Sorry, couldn't resist) I suffered most of my hearing loss in the early 70s from noise "outside human hearing range". Some from other war zone noise. Lots of hazardous noise is outside the range, some of it transferred to your internal ear  via vibrating bone structure.....

I don't think the cash-strapped Ruskies will be getting rid of the AK-74 anytime soon.  It's a small wonder they were even able to upgrade to the AK-74M.  

Pave, that's kinda what I was thinking.  I was reminded of the sonic weapons that really f-you up with sound outside the human hearing range, although in that case its low-frequency.  

I've been watching this topic with some interest as I work with a guy who served in the Russian Army from 93 to 98 as a admin soldier in Moscow. He's a kind of frooty guy who I swear was swishy when I first met hm, but seems to be about as normal as they come from that part of the world- anyhow, he swears up and down that the AK74 is old news and is being nearly completely scrapped in favor of the AN-94- most frontline Russian units have been converted since 1999.

Now, I just smiled and nodded because every time I try to get into a discussion with this guy, he wants to argue (no no, it was police units, "militia" involved in Chechnya, not regular army, with a few Spetznas mixed in) and the other guy I work with isnt much help because he is of the opinion that "hey, he was there, he should know best"....

So is this guy all wet? I thought due to budget problems in Russia that the AN94 was only seeing a very limited release....

It's likely he's unwilling to admit that his country is unable to make the transition do to economic trouble, so he's giving them the benifit of the doubt and hoping you don't know any better.  

Not many Russians I've talked to have been willing to admit much about the countries problems.  

is that the new ak they featured on discovery channel with the 2 shot burst mode?

yes.