repete
.338 Win Mag
I have a 1911 that the lands are worn almost totally gone, just because it's "worn" doesn't make it illegal.How worn does rifling have to be before it's illegal ?
I bet there is some overlap where there's enough to be legal but not enough to cause problems with your pattern.
Also, what twist rate is necessary ? I bet a 1" in 100' twist rate wouldn't affect your pattern at all. But you could still have full depth rifling....