ARSENAL’S SEMIAUTO LIGHT MACHINE GUN
Take a U.S.-made milled receiver, add a generous portion of Bulgarian RPK74 parts, and what do you get? The Arsenal RPK-3R
The affinity of many shooters for AK platforms started with the affordable AKs arriving in the 1980s—before the 1994 Assault Weapons Ban went into effect. The AK’s association as the “enemy’s weapon” has not deterred its popularity in the United States. This stems from many factors: ruggedness, reliability, price point, plentiful surplus ammunition, appreciation of 7.62x39 and 5.45x39 terminal ballistics, and the ever-increasing quality and quantity of aftermarket parts.
A sub-section of AK rifles I have always been drawn to comprises the RPK clone semiauto variants. Even more rare in this genre is the 5.45x39 RPK74 variant.
The RPK74 appeared in the Soviet armory in 1974 in conjunction with the AK74 assault rifle. Its role is to assist a squad or platoon in advancing toward an objective or defending from an attack using increased firepower.
To make the RPK-3R, Arsenal uses a U.S.-made, milled receiver mated to a Bulgarian RPK74 parts kit to create the civilian-legal RPK74 clone. These are limited-run production items that are quickly snatched up by AK aficionados. I was fortunate to get the first right-of-refusal for an unfired Arsenal RPK74 via a friend who knew I had always coveted it.
In my opinion, these types of rifles offer the civilian a level of firepower superior to most other available options. The RPK, originally chambered in 7.62x39, utilizes the same gas-operated, long-stroke rotating bolt operating mechanism made famous in the AK47. The RPK74 derives from the AK74 rifle, with modifications that mirror those made to the AKM to create the RPK.
The RPK differs from the typical AK/AKM as a result of a number of design tweaks intended to facilitate its role as a light machine gun. The RPK74 uses a longer and heavier 23.2-inch chrome-plated barrel, along with a different style of gas block with a channel at a 90-degree angle to the bore axis. The enhanced barrel improves heat tolerance during extended fire sessions. Another benefit of this barrel is a longer sight radius
for improved downrange accuracy, as well as an increase in velocity, compared to 14.5- or 16-inch barrels.
The barrel is mated to a reinforced receiver housing—reflective of its sustained-fire role and the punishment this entails for a weapon. The muzzle is 14mmx1-threaded for a flash suppressor.
The RPK74 is also equipped with a different front sight tower. The rear sight is outfitted with a sliding windage mechanism to improve fire accuracy and ease of adjustability. The RPK74 also comes with an integral bipod that folds underneath the barrel until deployed to offer increased stability when firing from the prone position.
RPKs typically feature a “club foot” rear stock, designed to allow the user to fire from the prone position more comfortably; this feature dates back to the RPK’s predecessor—the Degtyarov RPD light machine gun.
The original RPK used 40-round box and 75-round drum magazines to improve its combat volume of fire. It can also use standard 30-round AK magazines. As for the RPK74: While prototypes of 95- or 100-round AK74 drums and 60-round quad-stack box magazines exist, these have not reached high production levels. However, a 45-round magazine was created for use with it. The 45-round AK74 magazines (when available) can fetch $100, so the 30-round AK74 magazine works just fine.
KING OF THE AKS
The RPK74’s lineage to the AK assault rifle is obvious and beneficial in many respects. However, as with most weapons adapted to suit a role beyond their original design intent, the RPK74 has some drawbacks: The combination of firing from a closed bolt and fixed barrel translates into the operator having to use good fire discipline … or the RPK will overheat and fail.
Optimal sustained fire is around 60 to 80 rounds per minute. If overused/overheated, chambered rounds will “cook off” and will also cause barrel damage. The fixed barrel, combined with the inability to fire via belt-fed ammunition, causes many people to question the RPK’s utility as a light machine gun. Given the low sustained rate of fire, the semiautomatic Arsenal RPK-3R version featured in this article is not that much of a compromise, compared to the automatic military-grade RPK light machine guns.
Comparisons to the U.S. B.A.R. (Browning Automatic Rifle) are common—although not necessarily accurate, considering the different cartridges used. This includes their different operating designs: closed bolt for the RPK; open bolt for the B.A.R.
RPK development commenced in the late 1950s, was finalized by the Red Army in 1961 and entered widespread service in 1964. Each infantry squad was issued one RPK, along with a 75-round drum magazine. The RPK continues in use with numerous communist-bloc countries to this day, with hundreds of thousands produced. The 5.45x39-caliber RPK74 continues to serve in the current Russian Army.
The greatest benefit to Kalashnikov’s gas-piston operating system is its reliability in harsh environments. This reliability is mostly due to looser tolerances in the moving parts, thereby giving it more latitude to function when dirty from field conditions or not cleaned after firing hundreds of rounds. Arsenal AKs are often touted as the closest to a com-bloc weapon a civilian can get in America without filling out an ATF Form 4.
The most significant aspect of the Arsenal RPK-3R evaluated here is the U.S.-made milled receiver—unlike most AKs found in the United States, which feature stamped receivers. The receiver is created from a chunk of ordnance-quality steel and adds about a pound of weight, compared to a similarly configured stamped AK. The drawback is that the RPK-3R is a heavier rifle; however, the benefit is reduced felt recoil, which allows for more controllability during rapid strings of fire— the mission statement for an RPK-type rifle.
Echo Valley Training Center (EVTC) has installed two permanent “foxholes” by turning large-diameter concrete culvert pipes end-wise into the ground, complete with a firing step in the bottom. The protected firing positions were perfect for evaluating the RPK74 clone in its intended fire support
role. The center also features multi-stepped target berms that are strewn with reactive steel targets and fluid-drained automobiles varying in distances from 150 to 350 yards.
While it is certainly not comparable to a belt-fed machine gun with swap-out barrels, a relatively large volume of fire was possible, especially when used with a 45-round magazine.
It proved very possible to hit steel targets placed at 100, 200 and 300 yards along EVTC’s Range #1, which features a multistepped berm. Gilt-edge accuracy is not the goal with any RPK; it is a fighting rifle measured by a different set of parameters.
After orientation with the integral iron sights, a TruGlo Tru-Tec red-dot sight was added via the side-mounting bracket. It was a big enhancement in accurately placing rounds on target.
A range car placed 200 yards away could not withstand the RPK-3R’s withering fire. Rounds penetrated sheet metal and seats, along with anything else in its path as the 5.45x39 easily passed through the car. Only the wheel rims and engine block provided a modicum of resistance.
After a few hundred rounds on Range #1 smacking steel and chewing up cars, I moved to the Jungle Walk range, which allows for random target placements. The shooter can take advantage of cover and other terrain features while advancing down the winding, undulating path.
ARSENAL AKS ARE OFTEN TOUTED AS THE CLOSEST TO A COM-BLOC WEAPON A CIVILIAN CAN GET IN AMERICA WITHOUT FILLING OUT AN ATF FORM 4.
A positive point with the RPK-3R is portability. The 10.5-pound weight compares favorably with the U.S. counterpart M249 SAW that weighs nearly 20 pounds. This became very evident when testing it from standing and kneeling off-hand positions.
Individual and team exercises are based on real-world scenarios relayed to EVTC staff from the wide cross-section of students who visit this training center. The Arsenal RPK-3R had no problems during the various runs on the Jungle Walk. Each consisted of multiple magazines and engaging targets from 15 yards out to 215 yards. This is a good way to get an appreciation of a rifle’s portability and reliability under the pressure of field conditions.
Nearly 750 rounds of 5.45x39 were expended over a couple days of scenario-based testing. The smooth, minimal impulse of the 5.45x39-chambered RPK-3R has to be experienced first hand to be fully appreciated.
Although risking “excommunication” by 7.62x39 AK users (who are the clear majority in the United States), the 5.45x39 has a lot to offer. There is a reason the Soviets switched to it for their service rifle. Many of the same themes are echoed in Russia from when the United States moved to the 5.56x45mm: the ability to carry more ammunition for the same weight, lower recoil and muzzle climb, higher velocity/ flatter trajectory and so on. With the RPK-3R’s 23-inch barrel, 5.45x39 muzzle velocities approach 3,200 feet per second. This translates to a flat shooting round. For example, a 250-yard zero has only a 16-inch drop at 400 yards.
Some will be attracted to the RPK-3R for its proven potential as a weapon—it’s extremely reliable and rugged, and the volume of fire available from the RPK74 clone is hard to duplicate out of anything less than a belt-fed weapon. Others will want it because it is the closest opportunity they will have to owning a working replica of a proven Russian light machine gun.
Either way, the 5.45x39 RPK-3R proved enjoyable to shoot at the range and was amazingly effective in supplying downrange firepower. GW
… THE 5.45X39 RPK-3R PROVED ENJOYABLE TO SHOOT AT THE RANGE
AND WAS AMAZINGLY EFFECTIVE IN SUPPLYING DOWNRANGE FIREPOWER.
The RPK74 is a modified AK74 intended to fulfill a role as a squad-level light machine gun fed from 30- and 45-round AK74 magazines.
The AK side rail optics mount was used to attach a Leupold Mk4 3.5-10x scope to better realize the accuracy potential of the Arsenal RPK74 semiauto clone.
Arsenal uses a milled receiver on the RPK-3R. Here, to better conform to its intended role, a TruGlo Tru-Tec red-dot sight is attached to the side rail optics mount. The red dot was a huge enhancement in potency and accuracy placing rounds on target.
The RPK-3R front sight block has bipod legs attached behind it and a 14x1mm LH threaded muzzle with removable flash hider affixed in front of it.
Echo Valley Training Center’s prepared dug-in firing positions were tailor made to evaluate weapons such as the RPK74.
The RPK’s longer and heavier profile barrel, compared to a standard AK74, provides for improved heatresistance during long strings of fire.
Echo Valley Training Center’s stepped target berms allowed for the RPK74 to engage multiple targets-ofopportunity across various ranges. The decision to mount the TruGlo Tru-Tec red-dot to the RPK74 proved to be a good one.
The long and short of the AK 5.45x39 world: the RPK-3R (RPK74 clone) and AKS-74U Krinkov
All the ammunition tested produced acceptable accuracy results, but the Hornady 5.45x39mm 60-grain V-Max really shined.