The adapter you need if you have a yhm phantom or resonator - YHM 4302-24A 30 LT QD 5/8X24

I have the old YHM Phantom suppressor, the Resonator R2 and the Resonator K. This adapter is what you need in order to mount any of those cans onto a .308 rifle. Works well and I have a bunch of these. No need to shim or index. Just screw on to the end of your threaded barrel, torque to the appropriate specs and you are GTG.