I used some old Dominion 30-30 to fire form into 38-55, the 30-30 had 32 grains of powder, I remove 12 grains and reloaded the 30-30 bullets.
I had only three failures out of 15 brass, they formed , but I will be using a bit bigger charge to fully fire form.
They are a bit short, but for single shooting cast bullets, I think it will work fine.