What velocities did you see, and what alloy did you use? Powder coated or naked? Gas checked? Leading?...VP
Alloy is basically WW + 2% Sn; velocity is ~1,600 - 1,650 fps, which is fast enough to punch paper. The CB's are GC'd and sized to fit the bore of my SKS (.316"), but lubed or tumble lubed when I'm lazy. There is no leading at all with this load, VP.
Btw, a slow propellant like WC 860 with a small initiating charge of something like Lil Gun is also feasible and gives me 100% ejection and no leading.