The rifle has more to do with accuracy but the 308 and the old 222 were two of the best. All other things being equal the 308 is about as good as it gets. The 6.5x55 is another round that more than holds its own. Again with all other things equal. The Swedish mauser rifles had a lot to do with that cartridge being as accurate as it is. No other caliber of its size that I know of can equal the 6.5x55 when it comes to taking down Game. It kills way beyond what its ballistics say on paper.