I've been running H4831SC behind the 139 Scenars in a GAP build with a Bartlein 24" barrel. It's a faster burning powder compared to the typical flavors that get discussed with the 6.5 PRC. I'm at 2950 fps and don't feel like it's running hot. My freebore is 0.13" compared to the SAAMI 0.188" which keeps my OAL down near 2.88" and BDL friendly.
