remington wrote on Apr 19^th, 2012 at 7:24pm:

Anyone have advice on making lead bullets as accurate as that Sierra?

Slow down a bit! 16 or 17 grains of 4759 will get that bullet to 100 yards just fine and will be less inclined to deform in the throat or engrave off-axis, especially considering that you're using a soft alloy more suited to .45-70 than .30-40.

Also, size your bullet to fit the throat, not the grooves. That will probably be more like .311" but a chamber cast or throat slug will let you know precisely what you're dealing with.