MAX-31k Upper Receiver and Accessories
This upper receiver is designed to be used with the SWD, RPB or MAC M-11A1
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-11A1 or M12 lower receiver is illegal and potentially dangerous.
MAX-31k Upper Receiver
MAX-31k Upper Receiver
|Description||PRICE||The MAX-31k is a shortened version of our MAX-31A mk2 for the M-11A1 subgun. Overall length with our "k" folding stock is only 17-1/2". Rate of fire is between 650 and 700 RPM, depending on ammo used. With the addition of our K-Grip, Suomi 72 round Drum magazines can be comfortably used. Shockwave Technologies is working on a version of their excellent M-11/9 magazine for the MAX-31, MAX-31A and MAX-31k. Sorry, we do not plan on making one of these shortened "k" uppers for the M-11/9. #514A||$895.00||Backordered|
Shockwave 30-Round ZMAG-S for Suomi Magwell Upper Receivers
|Description||PRICE||30 round steel magazine for the MAX-31, MAX-31 mk2, MAX-31A, MAX-31A mk2 and MAX-31k. Also works in original Suomi M31 and K31 machine guns as well as the semi-auto versions of these guns. Shipping restrictions apply.|
|1 ZMAG-S 30 round Magazine. #ZMAG-S||$47.95|
Lage Fixed Sights
Lage-Low Profile Sights
|Description||PRICE||Low profile sights that cowitness with Aimpoint T1 or similar sights. Front sight has a fixed steel blade that is replaceable. Rear sight is adjustable for windage and elevation. A low mounting stock is recommended to get a comfortable cheek weld. Sight line is 0.625" above top of Picatinny rail. Made from 6061 aluminum finished in hard coat black anodize and steel finished in manganese phosphate. #243A||$144.98/pair|
Front and rear fixed sights
|These front and rear fixed sights machined from 6061 Aluminum and finished in black anodize. Front and rear sight hardware are standard M16-A1 parts. Sights are designed to be used with an Aimpoint T1 sized scope (or Primary Arms) with a 1/2" riser. Sights cowitness in the lower 1/3, in this configuration. Sight line is 1.025" above top of Picatinny rail. Rear sight weighs 1.7 oz. Front sight weighs 1.0 oz. #238||$119.98|
"k" Side Accessory Rails
|Description||Projected PRICE||Left and right side accessory rails for attaching additional accessories to the sides of the MAX-11k and MAX-31k Upper Receivers such as flashlights or lasers. Made from 6061 aluminum and finished in hard coat black anodize. 2.8" long, 4 slots. All mounting hardware provided. #407A||$34.99/pair|
Variable Buffer System
|Description||PRICE||The VBS is a Variable Buffer System consisting of three buffer spacers. When installed in the MAX-31k,
the rate of fire can be easily changed from between 662 and 1041 RPM, depending on ammunition.
Different rates of fire are achieved by installing a single or multiple buffer spacers.
See the manual for a more detailed listing of the rates of fire and ammo used. Ammo that has heavier or lighter bullet weight or is more or less powerful will have a different rate of fire.
While the VBS was designed with the intention of being used with our MAX-31k upper receiver, it can also be used with a stock M-11/9 to vary the rate of fire.
The VBS easily installs on your bolt assembly by simply installing it between the rubber buffer and the back of the bolt assembly. It is securely held in place with the ejector rod.
The VBS-1 is priced at $10.00 and includes one spacer. #421
Forward Canted K-Grip
Forward Canted K-Grip, Clamp On
|Description||PRICE||This clamp on K-Grip attaches to any M1913 Picatinny rail. The canted angle allows a natural shooting stance which is more comfortable than a straight vertical grip. The clamp is made from 6061 aluminum and finished in black anodize. The grip portion is made from black polymer and will stay cool during extended shooting sessions. #419A||$49.99|
The MAX-31k comes standard with a 1/2-28 threaded barrel and a Flash Hider installed. These barrels are for if you need a replacement.
5-3/4" Replacement Barrel
|Description||PRICE||Made from 4140 Chrome Moly steel, these 5-3/4" long barrels are finished in black oxide. Muzzle threaded 1/2-28.||$86.00|
9mm Flash Suppressor, 1/2-28 Thread
|Description||PRICE||M16-A1 Birdcage Style Flash Hider. Bored out for use with 9mm. These are the standard flash hiders installed on our 1/2-28 threaded barrels. #65||$15.00|
Bull Nose Thread Protector, 1/2-28 Thread
|Description||PRICE||Bull Nose Thread Protector for 1/2-28 threaded barrels. Originally designed for use with our MAX-11k, this thread protector can be used on any 9mm barrel threaded 1/2-28. 1" O.D. x 1-5/16" long with a knurl to provide an easy grip to install or remove the thread protector. An O-Ring installed in the thread protector seats against the barrel collar and prevents it from loosening or unscrewing during use. #429||$25.00|
HK 3-Lug Adapter, 1/2-28 Thread
|Description||PRICE||HK 3-Lug adapter threaded 1/2-28. We do not sell a dedicated 3-Lug barrel for the MAX-31k. You can add this adapter to use your 3-Lug suppressor. Mounts to any 1/2-28 threaded barrel muzzle. #610||$60.00|
"k" Folding Stock
|Description||Projected PRICE||This Folding Stock was originally designed for our MAX-11k upper receiver, but it is compatible with all of our uppers and
aftermarket M-11/9 upper receivers with taller sights than the OEM upper.
This stock features a folding mechanism that folds the stock down at a three degree angle to provide a generous clearance around the cocking knob on the left side of the upper receiver. It is designed with a thinner profile to fold very flat and provide a slim package. The folding stock mechanism and stock cheek bar are made from black anodized 6061 aluminum and the buttpad is made from black polymer. The stock adapter that attaches to the lower receiver of the M-11A1 is made from steel and is finished in manganese phosphate. Length from the butt to the rear of the stock adapter plate is 9-1/2". Available in lengths as short as 8". #327A
Fixed Buttstock, 8-7/8"
|Description||PRICE||This durable black polymer buttstock is is designed for use with the aftermarket M-11A1 upper receivers with higher sights or optics. This buttstock features a sling mount on the top rear of the buttstock. Easily installs with one screw and a threaded block that drops inside the lower receiver. Measures 8-7/8" from rear of receiver to end of buttpad. Length from backstrap of grip to buttpad is 11-1/8". Also available in 1" and 2" shorter length. Weighs 10.2 Ounces. #325|
|6-7/8" Fixed Stock. #325||$129.98|
|7-7/8" Fixed Stock. #319||$129.98|
|8-7/8" Fixed Stock. #318
Left Folding Buttstock, 9-1/2"
|Description||PRICE||This durable black polymer buttstock is is designed for use with the aftermarket M-11A1 upper receivers with higher sights or optics. This left folding buttstock features a sling mount on the top rear of the buttstock. When folded, it will not interfere with operation of the subgun. Easily un-folds and solidly locks in place. Installs with one screw and a threaded block that drops inside the lower receiver. Measures 9-1/2" from rear of receiver to end of buttpad. Length from backstrap of grip to buttpad is 11-7/8". Also available in 1" and 2" shorter length. Weighs 13.2 Ounces.|
|7-1/2" Folding Stock. #309||$209.99|
|8-1/2" Folding Stock. #310||$209.99|
|9-1/2" Folding Stock. #311
Canted Stock Adapter
|Description||PRICE||Canted Stock Adapter is designed for use with our Folding Stock Mechanism to allow the butt stock to swing low and out of the way of the cocking knob. This provides greater clearance around the cocking knob, makng it easier to access. The Canted Stock Adapter consists of two angled shims. One is placed between the folding mechanism and the stock adapter and the other is placed between the folding stock mechanism and the stock. #326A||$24.99|
ACE Rifle Stock Adapter
|Description||PRICE||This stock adapter is designed for use with the aftermarket M-11A1 upper receivers with higher sights or optics. Allows use of buttstocks manufactured by ACE LTD. USA. #32||$79.00|
AR15 Stock Adapter, M-11/9, M-11A1
|Description||PRICE||This stock adapter is designed for use with the MAX-11 mk2, MAX-31 mk2 and MAX-31A mk2 Upper Receivers or other receivers with higher sight lines or scopes attached. Attaches to M-11/9 or M-11A1 lower receiver. Allows use of AR-15 buttstocks. 1/2" of vertical adjustment. #611||$109.00|
Lage Folding Stock Mechanisms (FSM)
The Lage Folding Stock Mechanism (FSM)fits between the Stock Adapter and Stock.
Lage FSMs are designed to be easier to open than competitors' designs. Wrap your fingers around the stock
and put your thumb on top of the hinge pin and squeeze. Easily pops open. Locks in open or closed position,
pull from the side to deploy.
Our FSMs are manufactured with the Boss. Must be used with a stock adapter with a pocket machined for the Boss.
Lage Folding Stock Mechanism, Left or Right Folding
|Description||PRICE||The FSM can be mounted to fold either left or right. Will add .83” to your LOP. Weighs 3.5 oz. Manufactured from 6061 aluminum and finished in black anodize. Made in the U.S.A. Lage P/N: FSM1||$59.99|
ACE Folding Stock Mechanism
|Description||PRICE||Folding Stock Mechanism (FSM). This is the same FSM used in our folding stocks. The FSM is the standard Folding Stock Mechanism. It fits between the Stock Adapter and Stock. The FSM can be mounted to fold either left or right. Will add .75” to your LOP and weighs 3.5 oz.The FSM is manufactured with the Boss. The Boss is the raised (oblong shaped) portion on the Arm (small side). ACE P/N: A500||$59.99|
Suomi Drum Magazine Carrier
|Description||PRICE||Designed to attach to a GI web belt or MOLLE vest, these magazine carriers allow quick and easy magazine changes while also securely holding the magazine. Run, jump, squat or crawl and the magazines will not bounce out of the carrier. Spring tension of the magazine carrier can be adjusted by squeezing it together or pulling it further apart. Magazines are easily removed by pulling straight up, close to your body. Two ALICE clips are attached to the back for mounting the carrier to your belt or vest. #178||$40.00|
|Mag' Carrier YouTube Video|
Note: All prices are subject to change without notice.