I’m going to build a precision rifle on an AR15 platform and am looking for recommendations in chambering. Max 700 yds and I want no doubt about impacts on steel at that distance. Sometimes .223 doesn’t hit hard enough for a quick call so I’m looking for something with a bit more thump behind it. I have an Aero build in the safe to repurpose. It has a good trigger, stock and optics so I’m looking for the barrel now. This is strictly for games, not hunting or social work.