Exactly, skans. Zip guns have (generally) no rifling.
The OP believes that the steel (jacketed) bullets shot the rifling out of his Hi-Point pistol. Several posters (in at least one case, rather rudely, I might add) refuted even the possibility of such a thing.
I've seen stranger things, and most anything is possible when the facts are mostly unknown .... while I do doubt that correctly sized mild steel jacketed bullets could possibly remove the rifling of a properly manufactured .45ACP barrel, I have not seen the bullets or the barrel in question, or even pics ..... something's not right, but I have no evidence as to what it might be .....