I run a jp recoil eliminator on a 10” 7.62x39 (not exactly 300 bo, but close ish). It makes the recoil MUCH more manageable, easy to shoot. However the concussive force hammering those standing near by is miserable and punishing. Not something to shoot at a range around others, or in a closed environment.
I agree with OldSalty, if you are shooting around others, I’d look into a device with a blast shield, there are a few out there.