When I'll shoot slow I notice about every tenth shot is a little smoother and quieter. I don't think that it has to do with the barrel match. The smooth shot sounds a lot like a dm. I have an nt11 bolt in, and it is not broken in yet, think that is it. It does it with my dwell high and low. It still shoots the same distance. I have tried it with the bwing mod and without, same thing. What do you think?