New Products in stock! For more info, click the New Products tab.

Lage Manufacturing

MAX-10/31 Upper Receiver

MAX-10/31 Upper Receiver #529


Slow fire upper receiver for use with the M-10/9 or M-10/45 SMG. Uses 72 and 50 round Suomi M31 9mm magazines or DC-31 30 round stick magazines.

Barrel Upgrades-

The MAX-10/31 comes standard with a 1/2-28 barrel thread and a flash hider installed. The optional 3/4-10 thread is the original OEM thread of the M-11/9 SMG, for use with the standard M-11/9 suppressor. Select one of these options for a different barrel thread. Only select one.

3/4-10 Barrel Uprade +$20.00

3-lug Barrel Upgrade +$104.00


Manual Video

  • Description:
    The MAX-10/31 upper receiver is specifically designed to allow use of inexpensive, high capacity, 72 round Suomi M31 drum magazines. The longer receiver converts the M-10/9 or M-10/45 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 16-3/4" 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 600 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-10/31 attaches to the stock M-10 lower receiver without any modification to the lower receiver and uses your existing retaining pin. 50 round M31 "Coffin" magazines and DC-31 30 round magazines can also be used with the MAX-10/31. Suomi 36 round double feed magazines are not compatible.

    The picture above shows a MAX-10/31 with additional Lage Mfg. accessories that are not included with the MAX-10/31 upper receiver. Registered lower receiver is not included.

  • Features:

    Upper Receiver Image

    • Designed for use with a M-10/9 or M-10/45 submachinegun lower receiver.
    • Requires no modification of the lower receiver to install upper.
    • Uses Suomi 72 Round Drum Magazines, 50 round "Coffin" magazines or DC-31 30 round stick magazines.
    • 8-3/8" barrel threaded 1/2-28 at muzzle with "Birdcage" flash suppressor. Other barrel threads available.
    • 16-3/4" long accessory rail along top for mounting a scope or removeable iron sights.
    • Integral 5-1/4" bottom accessory rail.
    • Mounting points on left and right side of foregrip for mounting additional rails.
    • Side cocking, non-reciprocating, spring return charging handle on left side.
    • Ambidextrious "Paddle" magazine release.
    • 600 RPM rate of fire. Optional 610 and 700 RPM with use of VBS. Rate of fire with Sellior and Bellot (S&B) 115 gr. Ammo is 620, 675 and 765 RPM.
    • No modification of the magazines is required.
  • Specifications:
    • Overall dimensions of MAX-10/31 upper recevier:
      • Length: 17-3/8"
      • Width: 1-5/8" (2-3/8" across cocking knob)
      • Height: 4-1/8"
      • Weight: 4.1 pounds

    • Overal dimensions of the MAX-10/31 when assembled to an M-10 lower receiver with a 8-1/2" stock:
      • Overall length with 8-1/2" stock- 28-1/2"
      • Height- 6-5/8""
      • Width- 1-5/8" (2-3/8" across cocking knob)
      • Weight unloaded is 7.3 pounds
      • Weight of 72rd Drum Magazine: 2.1 pounds

    • Rate of fire:
      • Federal 115 Gr. FMJ- approximately 600 RPM
        Optional Rates of Fire with Variable Buffer System (VBS):
        One VBS Spacer installed- 610 RPM
        Two VBS Spacers installed- 700 RPM
      • S&B 115 Gr. FMJ- approximately 620 RPM
        One VBS Spacer installed- 675 RPM
        Two VBS Spacers installed- 765 RPM
      • Different bullet weights, such as 124 gr. And 147 gr. , as well as lighter or stronger
        powered ammunition, will result in slower or faster rates of fire. The rates of fire
        above are approximate. The rate of fire of your ammunition may vary.

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