5" cans work pretty well on .308 size cases and smaller.... not as well as full size cans... but they work.

A short barreled .300 is a little different animal... and you should probably be running a .300 RUM rated can... or at least .300 Win rated.

Not all suppressors are created equal... and I know you don't want to believe it.... but size does matter.

You better pray to the God of Skinny Punks that this wind doesn't pick up......