Zak is correct, over the barrel is mostly a waste at this point. Adds weight, heats the barrel, etc.
A buddy has one for his mk12. Not the best overall around can as there are better option now days BUT that can sounds so good. It’s quiet and the tone it produces makes it sound more quiet then it is. It’s a great canDon't think I have ever heard of anyone being disappointed with a OpsInc/Ron Allen can.