6.5x55. It somehow just makes em deader quicker. Next would be the 6.5-284. Love it too for much the same reason. third would be all the other 6.5mm cartridges. I have respect for all of them and own several that are not 6.5's but that little 6.5x55 just has a place at all times. I pull the trigger and whatever I am shooting at falls down, no drama, no short mad dash, just drt, the 6.5-284 has made a few more spectacular kills, and the 45-70 Encore (thumper is his name) is rather ruthless as well.