I'm not to sure about these. You can have a ton of BC and if the bullet is only going 2fps, so what, about the BC. The Boat-tail on this rig takes up allot of powder space, hence much slower speeds. The guys I know, who tried them, said they couldn't gain much ballistically, if any at all, just because of the reduced speeds. But hey, if they're cheap and hold together after something is slammed??..