Just got my suppressor for my xd40 in today, and went out shooting it. For some reason, it sounds like there is a ballistic crack when I shoot the gun, it's much louder than I have anticipated it to be. I am using federal 180 grain bullets, which *should* get rid of the ballistic crack, because it travels slower than the speed of sound. When I shoot the gun, however, there is a crack that I can hear going off into the distance. Is there any 200 grain bullets I can order to see if that is quieter?