Otter Creek Labs SPR Collar

Otter Creek Labs long SPR collar for most Allen Engineering and OCM5 suppressor mounting. Made from H900 heat treated 17-4 steel with a black nitride finish.

These collars will ONLY work with correct MK12 profile barrels as shown in the attached drawing. If your barrel is smaller in diameter than .747” THIS WILL NOT WORK and you will need to have a custom collar turned for your application. If your barrel is larger than .749” you will require either a custom collar or profiling or both.