Allen Engineering Custom AEM5 / AEM22 Collar for Colt M4 barrel
specially calibriated to fit Colt M4 barrel
In collaboration with Potomac Armory and Allen Engineering, this collar is designed to fit the Colt M4 and SOCOM 14.5" barrel. Many of Charlie's customers have invested in a great suppressor, the AEM-5 for their Mk12 clone rifle. This collar allows you to adapt your M4 rifle and use the AEM-5 suppressor.
The AEM-5 suppressor is old school, but still is one of the best military correct suppressors for the 5.56 NATO round. Leverage your investment in your Mk12 setup, and use the suppressor on your M4A1 rifle, or any rifle using a Colt 14.5" barrel. This sounds simple, but it is hard to get the AEM-5 to correct fit rifle barrels. Potomac Armory has commissioned a specific collar for the Colt M4 barrel. One thing that Allen Engineering has found, is there is no standard M4 barrel, and many people have purchased an M4 collar and had problems. To make it simple, Potomac Armory has made this collar work with the Colt barrel, and only the Colt M4 and SOCOM barrel. Ron Allen has told us that he gets many misalignments of the AEM-5 and AEM-22 on what customers tell him is a mil-spec barrel.
You must use a made by Allen Engineering brake, not a knock-off. Get the right stuff for your rifle.
Keep it simple, use a Colt barrel and this collar and your AEM-5 will work just fine. Make it even better and get your AEM brake pin and welded to your barrel.