My SBH 44mag has always leaded. Always in the first 2 inches of the barrel. Had some initial success with powder coating, but it will still lead.
Back to measuring for the umpteenth time. As of today, a pure lead slug pushed 2 inches into the muzzle measures .4300 across all lands. A pure lead slug pushed all the way through measures .4300 across 4 lands (2 measurements), and .4298 across the others.
That slug drops thru all throats with no pushing.
My .430 sizer sizes .4302-3. Those need a light push to go thru the throats. .431 sized bullet will not go through throats.
Pretty obvious I need throats opened up to get .001 over bore size?
The only other thought is that it is a well loved gun. It shows some forcing cone erosion, and has a bit of flame cutting. I've never pushed light bullets hard, and rarely shoot full power mag loads with 240g+ bullets, but a previous owner must have. Could these cause leading? Making it not a good candidate for throat work?