RE: Pa rifle requirements for deer
under "Big game regulations" "lawful arms and ammunition:" Deer and bear: regular seasons
manually operated centerfire rifles, handguns, and shotguns with all lead bullet or ball, or bullet designed to expand on impact.
muzzleloading long guns 44 cal or larger, muzzleloading handguns 50cal or larger
elk do have a minimum caliber of .27 and atleast 130gr bullets. deer and bear have no caliber restrictions other than it must be a center fire....17 rem, 22hornet etc would be legal to hunt bear and deer with if you so desired. i never remember PA having a caliber restriction other than must be centerfire.