My M66s throats were all undersized. I could not push through .358 cast bullets. Depending on the load i was getting some leading. With hotter loads it was fine but my .38s it would get pretty bad after 100. I was also getting lead deposits on the crane inside the cylinder which caused the trigger to hitch sometimes. I think it had to do with the throats swagging the bullets down which allowed gasses to go around the bullet but that was just a swag.
Anyways. @willie recomended Doug from cast-bullets and hooked me up with his email.
His prices were fair for honing the throats and i got the cylinder back tonight. Now my hardcast bullets push right through.
Im excited to try it out. I might try to make some time inbetween hunting and work tomorrow.
Crap pic i know.