.243 is a great deer gun. ive got one in an H&R handi rifle and ive shot deer at 400 yards and they generally pile up. the .30-30 is a good deer gun to alittle over 100 yards. after that it starts 2 nose dive. the .30-06 is one of the best deer rifles ever. if u can handle the recoil the .30-06 is the better choice, more knockdown power and further range. with the right bullet selection the .243 is no slouch. 100gr remington cor-loks and 95gr winchester supreme balistic silver tips work great