My Jap '86 has a 20 twist same as the 45/70 and launches the Lyman #193 and #643 without issue so I'm not looking for any surprises with the Gould bullet.At 30:1 it'll be on the heavy side typical of most Lyman molds and probably be around 350 ish I suspect.
Want to see that bullet REALLY expand ?
Secure a common BB into its' nose,...All I had was some Permatex gasket shellac when I did that,...That setup was just like a bomb on feral dogs.
.45s ARE fun with lighter bullets,...
Heavier bullets ain't bad, when driven at sane velocities, either.
GTC