I know this is A REALLY OLD THREAD!!! The catch is that I'm at work with a lot of down time so I'm necroposting again. My goto load ( when I can find the powder) for 77/75 class bullets is 25.2 grains of AA2520. My 20" RRA Predator pursuit will put 10 shots into group smaller than a quarter at 100 yards. I don't have a chronograph but according to the JBM website my estimated MV is 2750. I can get to 600 yards in one turn for paper punching, and at 300 and less it thumps coyotes like a hammer.
.308 Howa 1500 Varmint, EGW flat base, Medalist MkII stock
.223 Howa 1500 Varmint, EGW flat base, Medalist 6655 stock
RRA 20" predator pursuit, Magpul PRS, Vortex 6.5-20X44MM, SWFA SSALT Mount, ALG trigger.