I've hunted with my pre-64 Win 70, 264 Mag, 26" bbl, since 1975 using 60 gr IMR4831 under 140 gr Sierra SPBTs. Every hit was a pass-thru, no matter what range, on muleys, white-tails, antelope, coyotes, and all were DRT. I'm moving to Nosler 140 Accubonds but am still working up the load.