I reload a fair amount of 223 for a bolt action. A friend gave me 100 75g boat tail bullets. So far I have only found 1 recommendation for a powder. Does anyone have any suggestions?
Accurate 2520 is a good powder for heavy bullets in .223, especially in longer barrelled guns. Maybe not so much for 16" ARs, but should suit your use.
75 grain bullets shoot well in fast twist barrels, like 1:8" or 1:7". They don't shoot well in barrels with a slow twist. Most bolt guns have a slow twist. Reloder 15, IMR 4895, and Varget are popular powders for .223 heavier bullets.