The .257 Roberts Imp was difficult for me to get used to. For 10 years, I shot coyotes with a .358NM, my round ball and slug shooting muzzleloaders,the little .458 as well as a Rolling Block .45/70. With the .257 AckIMP, I kept shooting over the damn things - the little high speed bullets hitting right where the crosshairs were - high - go figure!