[Chief RID]

Here's the skinny. SBH leading in cylinder throats and where barrel screws to frame. Some fragments with light soft bullet loads. Throats measure .432 barrel measures .429 with restrictions at barrel screw in and a little at muzzle.

Have shot 500 rds or more of jacketed bullets through it. Trigger is getting very good and accuracy is improving mostly because of that and me getting more consistant and comfortable with the gun.

Marshall's Tech Guide is on order but I have not ordered any bullets yet. The local bullets only come in a 240 gr RN. They are bevel base also. I will probably go ahead and order Marshall's 265 gr gas check bullet and try it. Cast performance says they can get some .432 for me while I'm waiting on the Beartooth's.

I would really like to shoot a cowboy type light load for fun that would not lead and a performane hard bullet for hunting. Is this possible without lapping or should I start as soon as I read my tech guide instead of waiting on trying diffe4rent bullets?

 

[arkypete]

Lap!

 

[J Miller]

ChiefRid,
Besides lapping the barrel to get rid of the constriction, you will need to shoot bullets of at least .432 preferable .433.  The undersized bullets are allowing powder gasses to pass by the base of the bullet. This softens and partially melts the bullets which cause leading.  Also the bevel base magnafies this problem.  
I have the same problem with my .45 Blackhawk.  .452 grove dia, .454 chamber throats.  Most cast bullets are .452 bevel based.  A bad deal.  
And at non magnum pressures the bullets will not expand to fill the chamber throats.  
Slightly larger diameter bullets with flat bases would be my suggestion.