I use this in my M14's with 22" and 19.25" barrels.
However, I have also used it in my M40 replica build with a Shilen 24" 1:10 twist barrel. This load performed well. See information below and quickload pic.
M1Army
Powder - 42.1 Grains of H-4895
Primer - Federal Match Large Rifle
Bullet...