Allen Engineering Brake & Collar Kit

Brake and collar kit for brake mounted suppressors, also known as the “SPR Kit”.

Included with the kit:

Your choice of brake:

-1/2-28 Brake with .22/5.56 caliber aperture. SHORT external thread extension can be used with either a crush washer or spacer/shims. This is the MK12 “clone correct” version.

-1/2-28 Brake with .22/5.56 caliber aperture. LONG external thread extension for use with shims only.

-5/8-24 Brake with .30 caliber aperture. LONG external thread extension for use with shims only.

For more information about brakes and thread lengths, click here.

Thread protector

Shim kit

Your choice of SPR collar

Long – This was designed for use with Mk12 rifles and will work on any properly profiled Mk12 barrel.

Daniel Defense – This was designed for use on legacy Daniel Defense Mk12 barrels (pre 5/9/2022). To determine if this collar will work with your DD barrel measure the distance from the bare muzzle to the SPR step. If it is 2.3″ use the SPR DD collar. If it is 2.4″ use the SPR Long collar.

B-Mount – This was designed to convert your Mk12 barrel to accept B-Mount suppressors (AEM2, AEM3, and AEM4). This will work on any properly profiled Mk12 barrel.

Blank – This was designed to allow a gunsmith to fit a SPR collar on a non-Mk12 barrel. This will require a gunsmith to also profile your barrel, but this is a prefered option if your barrel is too thin to be re-profiled to match a Mk12. Click here to find the barrel prints.