Being in the service you will get to hunt in many different countries. If you go with either the 270 or 7mm you will be able to get ammo just about anywhere. A 243 has its place but, and I'm sure this will get some shooters in a tiff, and that is not my intent, it is a deer crippler. If you meet the height and weight requirements to get on active duty you will be able to handle the 270 or the 7mm just fine. If this offends anyone sorry. Just my experience and opinion.