I have the oppurtunity to trade a ARt15 I built a few years ago. It is nothing special, it is a Spikes lower with milspec parts and a 16" Rock River upper. I have some misc. Magpul dodads on it. I have a buddy that has a carbine length DPMS AR10 that wants to trade as he does more CQB training. I have a 308 bolt gun and shoot tactical comps. I like the concept of having one type of ammo to deal with. I would eventually want to have the gun rebarrelled at around 20-24". Could I have the new barrel chambered with the same reamer as my bolt gun when i rebarrel. What if any advantages to reloading for both guns would I see until i rebarreled the gun? How does 308 and 7.62 work?