One of the most frequently upgraded parts of Kalashnikov rifles is the stock. Although there is a variety of aftermarket stocks designed to fit the standard AK rear trunnions, the use of adapters that allow attaching AR-15 buffer tubes or Picatinny rail compatible stocks has also become quite popular drastically expanding the possible stock options for the good ol’ AK-47 and its derivatives. JMac Customs recently came up with a new family of products designed for attaching various stocks to AK rifles. This product line consists of rear trunnions called Modular Rear Kalashnikov Trunnion (MRKT) and stock adapters that are attached to each other via a new mounting interface called Infinity Mount.

JMac Customs Modular Rear Kalashnikov Trunnion

The trunnion part of the Infinity Mount represents an infinity sign shaped cavity milled into the trunnion with a hole drilled in the middle. The stock adapters have matching infinity sign shaped lugs with a threaded hole in the middle. The attachment of the adapters to the trunnions is accomplished by matching the Infinity Mount trunnion cavities and adapter lugs and installing an Allen screw from inside the receiver that goes through the hole in the trunnion and threads into the adapter. The two smaller threaded holes on the sides of the trunnion’s Infinity Mount are added to allow attaching Galil ACE stocks and Stormwerks hinged adapters.

AR-15 buffer tube adapter

The trunnions of this system are machined out of 4140 steel and have a nitrided finish. The adapters are made of 7075 aluminum and have a hard coat anodized finish. The trunnions are installed into the receivers by riveting them in, replacing the original rear trunnions. So although the installation of these trunnions does not require any modifications to the host receivers, to properly install them you’ll probably need to take them to a gunsmith unless you have the equipment and skills necessary for AK rivet installation.

AR stock adapter attached to the trunnion.

Currently, there are three MRKT trunnions and four stock adapters available. The trunnion options include:

1. MRKT-AKM for AKM/AK-74 pattern fixed stock receivers ($115.95)
2. MRKT DRACO for DRACO/MD65 receivers ($89.95)
3. MRKT-AKMS for AKMS pattern under-folding stock receivers ($127.95)

The four adapter options are as follows:

1. M4-MRKT for AR-15 stocks ($64.95),
2. RSA-MRKT for 1913/Picatinny rail compatible stocks ($34.95)
3. MRKT Folding Mech for attaching JMac Customs stocks ($94.95)
4. Non-Folding Adapter for MRKT Trunnions

You can see all the currently available MRKT adapters and trunnions, as well as some of the stocks made by JMac Customs, in the below-embedded video.

Lastly, here is a set of pictures showing the components of this system separately, attached to each other and installed on a rifle.

The AKM trunnion with an AR-15 stock adapter.

MRKT-DRACO trunnion with a Picatinny rail adapter.

The Folding Mech adapter.

AKM trunnion with a non-folding stock adapter and stock installed.

The trunnion for under-folding stock receivers comes with cover plates for the folding mechanism holes.

The AKMS trunnion with a Picatinny rail adapter.

The M4-MRKT adapter.

Folding Mech adapter.

Pictures by JMac Customs, www.jmac-customs.com