Features include a 14-1/4" 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-10 upper receiver . This reduces the rate of fire (ROF) from 1,100 RPM down to around 631 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-10/31k attaches to the stock M-10 lower receiver without any modification to the lower receiver and is provided with a retaining pin.
The picture above shows a MAX-10/31k with additional Lage Mfg. accessories that are not included with the MAX-10/31k upper receiver. Registered lower receiver is not included.
U.S. Patent 10,794,647 B2