It is not widely know in the US, but OPS INC / Allen Engineering supplied Canadian Special Operation Forces (CanSOF) with AEM3s (15h Model) and AEM4s (16th Model). Our suppressors were often used on Colt Canadas (Diemaco) C8 and L119A2 series of rifles. To properly mount our suppressors to these rifles the C8 Short Collar was made.
**We will use “CanSOF Collar”, “C8 Collar”, and “C8 Short Collar” interchangeably**
Most people see the CanSOF C8 Collar as the best option to mount a B-Mount suppressor (AEM2, AEM3, AEM4) to a 11.5″ FSB upper. However when people see the C8 Collar and Smith Enterprise flash hider, they also often mistake it for a one piece OTB design.
Like many other collar systems, the C8 Collar was designed for a specific barrel profile. It wont fit over any random barrel. What makes this different from other collars is that it is secured into place by the muzzle device instead of a set screw.
Below are the instructions on how to prepare your barrel to accept the C8 Collar.
First, you will need an OPS/AE muzzle device. We recommend avoiding the OPS Short Brake and instead use the OPS Long Brake, Smith Enterprise Flash Hider, or FCD Flash hider.
Second, if you are putting this collar on a 11.5″ FSB barrel you will need to remove the bayonet lug. The lug will prevent the proper installation of the collar. While the C8 Collar was often used with FSB barrels, the FSB is not required and any barrel can be made to work with these collars.
Third, you will need to profile the barrel to accept the collar. The collar is designed to fit over Colt Canada barrels which often have the .615″ OD past the gas journal. I have included the barrel print bellow for you to use. No, this is not an OTB design and therefore requires a specific barrel profile. It wont fit on barrels that have an OD larger than .615″ and it wont provide proper suppressor alignment on barrels with an OD smaller than .615″.
Fourth, add your C8 Collar to your barrel. There should be almost not wiggle room between the collar and your barrel. Also step in the collar should sit on the shoulder of your barrel.
Fifth, add your muzzle device. As you tighten it to your barrel it should push against the collar securing it to place. You can add shims to properly time your muzzle device.
