cra1948s recommendation of the lasc is good as is flintlocks on fast powders.
For moderate velocities in numerous 30 cal rifles, and 165g and up weight bullets, i have had very good luck with 4227, 2400, 5744, and sometimes Unique. My best accuracy seems to be around 1500 fps.
If these are over the counter bullets, it may help to get a size that is large enough for you to tailor the diameter to match your rifle. Cast bullets is a whole nother hobby that is fun but requires some work and fiddling around. It helps to have a neck expanding die so you dont shave lead seating a bullet.
No doubt others will chime in with great suggestions.
Last edited by Centennial; 07/30/21.
