NFA Warning

This upper receiver is designed to be used with the SWD M-11/9 submachine gun. NFA (National Firearms Act, Title 26, United States Code) rules apply to its use and possession. It is the owners/users responsibility to comply with all local, State and Federal laws and regulations in the use of this product.
Possession of this upper receiver with a semi-auto M-11/9 lower receiver is illegal and potentially dangerous.

MAX-31 mk2 Upper Receiver

The MAX-31 mk2 upper receiver is specifically designed to allow use of inexpensive, high capacity, 72 round Suomi M31 drum magazines. The longer receiver converts the M-11/9 into a carbine sized submachinegun and provides greater control and handling. The 72 round drum magazine allows you to shoot longer between magazine changes, enabling you to save precious time during matches.

Features include a 18-1/8" long accessory rail on top and hard mount points for additional M1913 rails on right and left side of front handgrip. Bottom rail is integral. Contained within the upper receiver is a heavy weight bolt assembly with a longer length of travel than the stock M-11/9 upper receiver . This reduces the rate of fire (ROF) from 1,100 RPM down to around 770 RPM. Due to the reduced ROF and longer bolt travel, muzzle rise is reduced, the gun feels much smoother in operation and easily stays on target. The MAX-31 mk2 attaches to the stock M-11/9 lower receiver without any modification to the lower receiver and uses your existing retaining pin. 50 round M31 "Coffin" magazines can also be used with the MAX-31 mk2, but the 36 round double feed magazines are not compatible.

The picture above shows a MAX-31 mk2 with additional Lage Mfg. accessories that are not included with the MAX-31 mk2 upper receiver. Registered lower receiver is not included.




Steel cased ammo is not recommended. Use of reloaded/re-manufactured ammo will void the warranty.

Note: All prices are subject to change without notice.