When you shoot, it's much harder (or impossible) to shoot all your bullets into the same bullet hole than to shot wherever you want to. It's a CMA training method that may not be used in boxing.
I really stink at the boxing speed-bag. Too bad. I always thought it looked so cool. Anyway, when I watch boxer friends working the speed bag, they repeat the same strikes to the same target with great precision and rhythm equal to anything I've seen in CMA. Heck, if somebody were to tell me that the Chinese invented the speed bag, I wouldn't find it surprising!