.243 will kill deer just fine and has a pile of them over the years. Now people are using. 223 and. 300 and I don't hear people fussing about these calibers. Personally I shoot. 308 . There's not enough difference in the recoil of. 308 and. 243 so as far as a young hunter or female I would pick .308 for them. Still not sure on .223 and. 300 even though they are killing alot of deer.