Swaged bullets from Hornady are around BHN 7 or 8, generally leading isn't a problem below 800~850 fps. Missouri Bullets cowboy bullets are BHn 12 which should be good for around 1000~1100 fps. Note you can run into leading problems when running hard bullets like Missouri below 1000 fps due to the bullet base not "bumping" up to to throat diameter and case cutting of the base.

Swaged bullets are good enough for cartridges like the 38 spl, 44 spl, 44 Colt where normal velocities < 900fps.