I have been collecting the loads for long range .223 here are some:
77 SMK (COL of 2.25):
22.5 IMR 4895
24.5 AA 2520
I assume these charges are very close for 75-80 bullets.
55/52 grain loads (for 100-200 yard practice)
(COL of 2.25)
26 IMR 8208
25.5 IMR 4895
25 AA 2015BR
****NOTE!!! ALL LOADS TESTED BY ME ARE MOLY COATED. YOU MIGHT FIND YOUR LOAD IS .5 GRAIN LOWER****
77 SMK (COL of 2.25-magazine length Ar-15):
24.5 R15 -this is the THE “go to” Highpower “across the course” load. Used for 75/77/80′s at magazine length and seated out to the lands. R15 has a lot of black carbon, that looks like hell but doesn’t really effect anything accuracy wise of function wise. I think it has a an anti-fouling additive that makes the carbon look real black. No more heat sensitive than Varget in gas guns. Throws to the .5 grain in a progressive… which is still good enough for darn near everyone, including High Master Highpower shooters.
23.3 8208- this is the the NEW/LATEST “go to” Highpower load that everyone is raving about. I have not tried it, but their is ample evidence this is a shooter. I tell you what, this stuff is CLEAN BURNING!!! I love the small kernels too… It throws like H322 (and looks like it) and is darn near as accurate out of a progressive as a ball powder. It probably holds +/- .1 no problem without the usual long/short throw every so often.
23.5 Varget- this was my 300 yard load for across the course Highpower for many years. Seems like everything 1-9 twist or more shoots this load very well. I found Varget to be very sooty (with kind of a grey colored carbon) but I kept my space gun well greased and never cleaned it (the old Derrick Martin trick of grease/strip/grease works very well), so it must not have been too bad. My Kreiger barrel lost little in the way of accuracy over a week’s shooting. Throws the same as R15.
21.7 H322- this is the pet load of a guy here on this forum and he swears by it. I am going to test it, as I love this powder. It has those small kernels that work very well in progressives and an anti heat coating.
22.5 IMR 4895- this is a load I used for 8# of powder. It is at least .75 MOA in an AR-15. It works MUCH better in some guys guns… Like .25 MOA, but I never got it. Good for surplus powder if you want to shoot accurate on the cheap. See test by Derrick Martin.
24.5 AA 2520 – VERY accurate load, and was very popular when this powder was cheap. Loads awesome in progressives, as this is ball powder. VERY!!! Heat sensitive in the summer.
I assume these charges are very close for 75-80 bullets. Most guys I know used the same powder charge (shown above) no matter the bullet or seating depth within the 75-80 grain range. Of course, some tweaking up or down might make a difference… but darned if those guys doing extensive testing don’t keep coming up with almost the exact same loads…