my cousin purchased a 264 wm, and wants me to start loading for him. He bought 6.5 140 grain ssts. i have shot ssts out of my 257, but they are flat based. these are boattails. they tore up pa whitetails in my 257, anyone use them in a 264 wm before? and does anyone know why they are boattails in the 6.5 cal, and flat based in the 25cal? thanks, Paul