8" barrels for 5.56 certainly isn't optimal, but there are certain loads that work quite well with it. Your range is just heavily limited with them.
Heavy loads actually tend to do better. The Mk262 77gr OTM loads work very well because they will yaw easily. The best option is actually going to a Barnes TSX bullet. The 70gr TSX is designed to optimally expand all the way down to 1800fps, but they'll come out of an 8" barrel at around 2100-2250fps or so. 45gr and 50gr TSX bullets will be much faster, and still perform well. Short of those loads though, an 8" barrel is not good for much for actual offensive/duty use. They're fun to shoot, though. But holy shit do they have a lot of concussion.
Last edited by Reedo302; 09-23-2012 at 11:50 PM.