Either way its a none issue for me. I have both bore diameters in various 7.62x39 chamberings. AK's and SKS's get the 310 bullets and rest get the 308 bullets. I've never noticed much degredration in accuracy between the 308 and 310 bullets in the AK or SKS. Entirely different story with American made bolt guns or European manufactured bolt rifles. Makes big difference in those rifles so simple thing too remember - use American in American rifles (308) and European in European rifles (310).

Side note if you want your barrel too last don't shoot the steel jacket bullets that are copper washed. Easy test is too use a magnet.