Aa2230 / Aa2460 / Aa2520 ???ar15 1:7

What is the difference between these powders? I tried looking on their web sight, but that information was pretty limited. I currently use AA2230 with 68/69 grain HPBT. I have seen some published loads for AA2460 with the 68/69 grain HPBT also. Does one powder do better with lighter bullets and one does better with heavier bullets? Thank you

2230 is the fastest, and works better with light bullets, 2460 is a little slower, and 2520 the slowest. I use 2520 with my 68/69 grainers as well.

I use 2520 with 77 gr in a 1:7 twist barrel and 2230 with 55 gr in a 1:9 twist barrel.