Andy the Boss does work.I have two one on a BAR and an ABOLT.On the A-Bolt I can move the Boss from 2.5 to 2.8 and my groups go from 2+ inches to less than .5 of an inch.The best thing about the Boss is you can use different ammo,weights.just remember your setting for the ammo/load and right it down then find the right settings for another load.I use mind with the CR hunting because the muzzle brake one is so load,if I were doing all my shooting at the bench I would use the MB it reduces recoil a lot.