YES and YES!!! I've never had a M99 .308, but it handles it quite well and very accurately I might add. I guess I've never had a .308 because I've had a .300Sav in a 99 forever and to me the two are almost interchanageable. Opps!!! I know interchangeable is a BAD word around rifle loonies. Please don't try to interchange them. That's a NO-NO!! I meant the two cartridges are quite similiar. Actually the true answer to your question is that the original 99's(1890's-early 1950's) action wasn't quite long enough for the .308. Of course the .308 wasn't around then either. Not long after the .308 was introduced that problem was corrected and the 99 was chambered in .308, .243 and even some .358 and .284 Winchesters.