Re: 264 win mag help?
Danshae, My 264 has so much freebore that the only bullet I can shoot with good accuracy is the Hornady 160 grian round nose. I tried IMR7828 and I was getting extreme diviation in velocity and the accuracy just wasn't there, although some 264 loaders swear by it but I swore at it. As far as US869, I have never tried it in anything and stay away from ball powders in rifle cartridges but that is not based on anything but my own bias. My rifle (a real heinz 57) is a custom Encore barrel from E. Arthur Brown Co. that started out as a 6.5/06AI with 1 turn in 8" twist and then was sent to OTT (On Target Technologies) and Mike there rechambered it to 264 Win Mag. The barrel likes the bullets seated kind of close to the lands but I don't encroach too much as this is a powerful cartridge and it needs a little room, I try to seat around .010" from the rifling. For the medium large cartridges, which I consider the 264, I haven't found a better powder than H1000 but I haven't tried everything on the market. My S-I-L has a hand-me-down Weatherby Mark V Hand Select chambered in 257 Weatherby Mag, which has about the same case capacity as the 264, and that old rifle wouldn't shoot under 2.25"-2.5" at 100 Yds until he tried some H1000 with a rather heavy for caliber bullet which gave him .5" accuracy. H1000 seems to be a very predictable powder in cases of the rather large variety with the heavier bullets. I don't recall my exact load specifications and would rather you work up your own load as my rifle isn't a plain vanilla factory job which makes it rather quirky.