Re: Powder for new .223 80GR Sierra BTHP at 600yds
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The 80 is 3 grains heavier but has a shorter bearing surface than the 77, so pressure-wise the 80 can take the same or more powder before having issues. That said, TAC is not optimum for either bullet, and if you try to push the velocity with it you will get pressure issues.
Any of these powders will do the trick - RL-15, Varget, VV N140, H4895 - and give you more velocity without pressure issues than TAC. AA2520 is another candidate if you like the ball powders. The first 3 powders named have the load hover around 24 grs for an all weather safe load resulting in velocity around 2700 FPS out of a 20" barrel at 80 degrees F, while the H4895 is generally run .4-.5 of a grain behind them to achieve similar pressure and velocity.
Price and availability issues aside, VV N-140 is by far my favorite powder in the 223 with these weight bullets. Price and availability taken into account, I run RL-15 for 200 and 300 and the 140 for 600 on back. No issues with running 140 on top of RL-15 as far as the shots being on call at 600 for the first few rounds. No settling in when changing loads with the two different powders.</div></div>
Concur.
You might also add Vihtavuori N135 and N540, both a little expensive and sometimes hard to find. Both Reloader-15 and varget have been more available lately.
I've used 24.5 to 25.0 of Varget in commercial Winchester cases for many, many years now, but I also use a Tubb Carrier Weight to keep the primer edges nice and round (instead of flattened).
