Allen Engineering
Perfect replacement for Ops Inc. #12, fits AEM-5. This is for the Mk12 clone build, as well any other great rifle build. This is the longer collar, which will fit the Mod1 and other SPR profiled barrels.
This Collar will is designed to the fit the Mk12 Mod0. Here is the link to the Mk12 AEM5 long collar. The long collar fits most builds, as long as the barrel is properly profiled. The Mod 0 has a much closer clearance to the front sight base, and thus you will need this shorter collar for the Mod 0. The truth is that this collar will fit most all builds, but is absolutely needed for the Mod 0 build with the shorter clearance between the barrel shelf and the gas block. Note: Not every Mk12 or RECCE barrel is correctly profiled. And some will accept the collar, but will not accept the suppressor.
Ron Allen builds these one by one by hand. He was the engineer that created the Ops Inc. collar and suppressor. Well worth the money for any precision 5.56 mm rifle build. Ron created the collar while working at Ops Inc. This is the exact same collar. If someone wants to argue otherwise, you might find something where a roll pin is .001" in a different spot, but I have not found it.
This is 100% genuine Allen Engineering. There are alot of companies making knock-off "Ops Inc" collars. Even some rifle manufactures building very nice Mk12 rifles with the wrong brake and collar. If you are not going to run a can, the knock-off or generic Ops Inc might work fine. But for the small price to get the real deal, we do not work with, nor endorse any other manufacturer. The tollerances to get the profile, collar, the threads, all in the right spot to align the suppressor are very tight, and Ron tells us he is seeing baffle strikes on his cans caused by another manufacturer's collar and brake, or a poorly executed SPR profile on the barrel.
Note: this is only the collar and set pin. For a complete installation, you will also need a brake and thread protector. Click here for Allen Engineering brakes, collars and thread protectors.
Some pics show the long and short collar, for comparison.