Not a Blackhawk, but around '99 I bought a stainless Vaquero convertible. Occasionally shot BP 45acp in it. One thing with mine, since it headspaced on the case mouth, I found that some brass was too long and would bind in the cylinder against the recoil shield. After I determined what was the max length that would chamber and function, I would sort my brass before loading 45acp ammo for that gun.