J300, I found a load for the 180gr Nosler Ballistic tip with 7828 that shot 3/4 moa 5 shots at 3494 fps and s/d 16. This bullet makes no sense for this caliber, so I dropped it. The factory 225gr Barnes X load shot 3/4 moa 5 shots at 3172 fps and s/d 22. I killed a Blackbuck with it, but it appeared that the petals sheared off. He ran about 75 yds with no blood trail. Dropped that load. I never found a good load for the 250gr Smkhp. The best 300gr Smkhp load so far is 3/4 moa consistent at 2760 fps and s/d 9. It's 108grs H-5010, 215M primer, oal 3.8", with very light compression and is a very mild load. I think 2850 fps is a reasonable goal. I get about the same accuracy at the single load length of 3.930" overall, (full caliber in neck), with no compression of course. The 300gr is the only bullet that can reach the rifling in my chamber, at oal of 4.115". 3.8" is maximum magazine load length in my rifle, and I like to load ammo that goes in the magazine.
This 300gr Smkhp load delivers 3300 ft lbs of energy at 600 yds, still has 2200 ft lbs at 1000 yds and over 900 ft lbs at one mile. All this is at 100' above sea level and 75% relative humidity. The performance just gets better at higher altitudes. I believe it would dispatch a moose or caribou cleanly. Probably a big bear too. It flies straight, bucks wind, and hits hard. That's why I'm concentrating on this bullet.
The rifle is on a MK V action, with a #7 Shilen Select Match barrel crowned at 27 1/4", chambered with a factory dimension reamer, and has a single chamber muzzle brake. It weighs 12 1/2 lbs in a reworked factory .460 stock with a 4 1/2 x 14 x 50 side focus VX III L/R scope. I expect to tune it to 1/2 moa or better. Just need some time!
Hope this helps get you started, Tom
