Re: ops inc .308 can on a .223 ar-15
I have not done this specifically with an Ops Inc. can, but it generally works well to use a can made for a larger caliber on sub-calibers (i.e. - using .338 can with 338LM, 300WM, 308Win, 6.5mm rounds, .223, etc.).
You may not get quite as efficient a sound signature reduction doing this, but the idea is to have one can that can be used across the board on different calibers.
As long as the suppressor has the same thread pattern or mounting system for each different caliber's barrel...FIRE AWAY!