There are a lot of best cartridges. Depending on where and what kind of terrian. I have shot a lot of deer with calibers from .243-.300win mag. My two favorites have become .260 and 7-08 in a 5.5 pound rifle. Short compact and light. With federal Fusions the Deer are DRT 99% of the time. And when they not they'd only go a few yards. little meat damage with great terminal ballistics. Little recoil they are a Dream to shoot and being very very accurate. JMHO