THE INCREDIBLE SHRINKING AK: ARSENAL’S NEW SLR-106U
Text & Photos by Jeff W. Zimba
Only a few short years ago an AK-style rifle with a short barrel was typically a fairly expensive, custom build. In the last 10 years, very short AKs, or “Krinks” as they are often referred to, have gained massive popularity within the US shooting community. There has been an influx of images we see on the daily news of fighters (both good and bad guys) carrying these short rifles, and combined with our never-ending affair with custom gun modification it seems like a logical progression. Arsenal, Inc. of Las Vegas has watched this interest build and is proud to offer their latest addition to the AK lineup, the SLR-106U. For the first time in the USA, a factory Krinkov rifle can be as close as a simple phone call away.
If you have been following the pages of Small Arms Review over the last 8 months, this newest offering from Arsenal, Inc. may not be much of a surprise. We introduced the Arsenal SLR-106FR in the February 2007 (SAR Vol. 10, No. 5) issue and the SLR-106CR in the June 2007 (SAR Vol. 10, No. 9) issue. Continuing to build new innovative designs in the same, lightning fast pace, we are extremely pleased to learn of this latest configuration and are pleased that Arsenal, Inc. has chosen Small Arms Review to introduce it to our readers first.
Like the other Arsenal firearms in the Model 106 family, the SLR-106U is chambered in 5.56x45mm and continues to have the left-side, folding, polymer stock. It also utilizes the same Bulgarian Mil-Spec stamped receiver and the US-made fire control group as the others in the 106 line. The 2-stage trigger that we first tested in the SLR-106FR and again in the 106CR is still included in this latest model much to our satisfaction. We measured the trigger with a Lyman electronic pull gauge and recorded an average of an 8.2-pound break on the second stage with very little movement. Other than the US pistol grip specific to this rifle series almost everything else is drastically redesigned.
As the SLR-106U is shipped from the manufacturer, it has a 16.25-inch hammer-forged, chrome-lined barrel. It has the standard twist rate of 1 turn in 7 inches to allow better performance with heavier ammunition. The 90-degree gas block and front sight combination is chrome lined for increased durability. The sight assembly includes the standard 24mm right-hand thread to accept several common 24mm muzzle devices in case the shooter desires to register the rifle as a Short Barreled Rifle (SBR) and cut the barrel to its originally intended length. (Here at Small Arms Review we knew what length the readers would be interested in so we are testing the modified version with the 8.5-inch barrel in the first place.) Should the owner decide to leave the rifle in its Title 1 configuration and keep the 16.25-inch barrel (or live in an area where SBRs are not an option) a PBS-5, non functional, replica suppressor is available to slide right over the barrel and attach to the 24mm threads.
As with the other rifles in the Arsenal lineup, there is a companion model available to the SLR-106U. It is the SLR-106UR, with the letter “R” indicating the addition of a scope rail. In this case it is a riveted Warsaw Pact scope rail, which will not work loose and will accept an abundance of available scope mounts.
Looking at the many differences between the 106U and the others in the 106 family, aside from the barrel on an SBR variant, the most noticeable attributes are the length of the handguards and gas piston. The visible portion of the lower handguard on a standard length AK measures approximately 6 inches in length. The same portion of the lower handguard on the SLR-106U is a little less than 4.75 inches. The newly designed handguards are made from high quality polymer and incorporate stainless steel heat shields. The raised-rib design is comfortable and functional and the heat shields did their job of deflecting heat away from the hands of the shooter during all our testing.
The bolt carrier itself is slightly modified although it may not be immediately noticeable. The diameter of the bolt carrier directly behind the gas piston and in front of the charging handle has been turned down to a diameter of approximately 0.566-inches to facilitate the smaller opening in the hinge block of the 106U. The diameter of an unmodified bolt carrier in this area is 0.625-inches. Much more noticeable is the shorter gas piston of the SLR-106U measuring only 2.25 inches in length compared to the SLR106F that measures 5.75 inches.
The top cover of the SLR-106U is the same length as a standard AK variant but it is front hinged and not removable. Directly under the front hinge is a spring-loaded captive piston that acts as the rear latch for the top handguard. After opening the top cover and removing the op-rod, the top handguard can be removed by simply lifting it up. This is due to the shortening of the rear sight block in front of the barrel trunnion, which no longer has room for the standard handguard latch.
Since the rear sight block has been severely shortened, the standard front sight is no longer utilized. In its place is a 2-position U-notch rear sight that is located on the top cover. In the first position it is utilized for distances up to 300 meters. For distances out to 500 meters it can be flipped to the second setting. The sight radius is approximately 9 inches compared to 14.5 inches on a standard length AK.
The stock of the SLR-106U is the same high quality left-side folding stock found on the others in the SLR-106 lineup. There are a few interesting features about the stock that should be of particular interest to fans of the Krink-style rifles. First, the stock is pinned in place with a 4.5mm hinge pin. This pin can easily be tapped out and the stock replaced with a more traditional triangular metal folder for a more “original” look and feel. Secondly, in anticipation of this stock change, the 106U has enough US made parts so the stock needs not be counted towards 922(r) compliance. The rifle contains only 9 foreign made parts, even counting the 3 primary magazine parts, the magazine body, magazine follower and magazine floor plate.
All 3 variants of the 106 family were tested for comparison during this time with the 106U. There is a lot of speculation about the loss of muzzle velocity that is inherent with such a short barrel, so we compared the 16.25-inch version and the 12.5-inch version beside the 8.5-inch version of the 106U. Testing was completed with a PACT MKIV XP Timer & Chronograph using Wolf 62-grain FMJ and was measured at a distance of 8 feet from the muzzle. Testing was concluded with no muzzle device and again with the 4-piece muzzle brake for comparison. Three strings of 5 rounds each were measured, and the average test results are in the included chart. In summary, the fastest average muzzle velocity measured was 2,739 fps with the 16.25-inch barreled 106F and the lowest was measured with the 8.5-inch barreled 106U at 2,230 fps.
20-round groups were fired at distances of 50 yards and again at 100 yards with each rifle. Open sights were utilized from a bench. Since all rifles tested have a rifling twist ratio of 1 turn in 7 inches we used the heavier 62-grain ammo for test purposes. At 50-yards the 20-round groups fired averaged around 4.5 inches. This shooting was done in a rapid-fire manor. The groups at 100 yards were a little larger but only slightly. The 12.5-inch barreled SLR-106C that we tested in an earlier issue of Small Arms Review (Vol. 10, No. 9, June 2007) performed extremely well at both distances as well as the 16.25-inch SLR-106F. We expected to see a larger spread in accuracy between the 106 series rifles as the barrel lengths were reduced but all were comparable when fired under exactly the same conditions. Maybe for a future issue we will test the models equipped with the scope rails with some quality optics and some match grade ammunition, and see how these rifles are really capable of performing.
While the group sizes showed no enormous changes as the barrels got shorter, two things that did weigh in much differently were the aforementioned muzzle velocity readings and the amount of noise and flash that increased. The target spotter assisting the writer was quick to speak up when the 106U came to the bench and everyone in a reasonable proximity craned their necks to find out what just changed on our shooting bench. If the shorter barreled versions are being fired from an enclosed area, even one with a simple roof and small knee walls, double hearing protection may not be a bad idea.
In this writer’s opinion, the Arsenal SLR-106U can be summed up in 4 simple words: It is about time! Custom rifles of this type and configuration have been gaining incredible popularity in the United States of late, and this rifle series has been one of the last to have caught on. Short Barreled Rifles (SBR) of other types that were once only available as custom builds have been increasingly available as “factory” guns in the last decade. Several companies have been offering short AR-15 type rifles for many years and lately there are a few H&K type rifle manufacturers who have also jumped on the bandwagon. It is nice to see Arsenal addressing the desires of the die-hard Kalashnikov fans with their latest offerings, lastly the 8.5-inch barreled SLR-106U. Although they are shipped from the manufacturer in a Title 1 configuration, the hardest part of the SBR conversion is finished. All the end user needs to do after approval of their BATFE Form 1 is shorten the barrel and they are good to go. It won’t be long that a few enterprising Title II Manufacturers will be offering completed SLR-106U SBRs in the not-so-distant future. If you are a fan of the Arsenal family of Bulgarian AK variants and you want something a little different for your 5.56x45mm collection, this rifle will fill that open space in the vault just fine. Be forewarned though, an 8.5-inch 5.56x45mm rifle is an attention-getter at the range, especially around dusk. It is as stimulating to the audio senses as the visual senses so it is hard to conceal as a “regular rifle.” Because of this extra attention, you will need to make sure you have plenty of extra ammo for your friends, both old and new.
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