I am looking at acquiring a new rifle and would like a rifle not quite 308 or as small as the 223 for bullet weight and muzzle velocity. What I am trying to do is stay with the standard AR15 without stepping up to the weight and size increase of the AR10. Can anyone tell me where the caliber line is drawn, and which is the best to go with. I was looking at the Remington 260 but all I have read says it's just a necked down 308 so I am back to the AR10 situation. Any help will be appreciated and I would appreciate any heads up on any applicable threads I may have missed. Thanks
