Had quite a bit of lead throughout the barrel of my new Rossi 92 45 colt with 24" barrel. Experimented with various alloys (50/50, ACWW, WCWW) and it didn't matter. Was loading this 284 gr. SWC over 13.5 grains HS-6 (Ruger only). Leading was sufficient enough to effect accuracy after 10-15 rounds. Slugging showed .4515 (and my bullets were sized .452) I decided to firelap with 10 rounds using LBT compound. That improved things so much that I went ahead and did 10 more.
Bright and shiny now and stopped leading except the first 1/2 inch of the breech. Now, with 50/50 bullets at .452 I get about 1/2 inch of leading and with WCWW I get lead throught the whole barrel. I am thinking this is definitely a "fit issue" since the softer bullets would be obturating, but it slugged out at .4515 so that shouldn't be the case.
Yesterday I received the Cerrosafe from FatElk and cast my chamber/breech and the muzzle. Guess what, after 30 minutes the cast measured .452 and at one hour it measured .453! Looks like my slugging wasn't real accurate. This explains the location and amount of leading I was getting. I will jump up to a .453 bullet and .454 if needed. Hope this will fix it.
I think I had two different problems.
1. The bore was so rough it was grabbing lead from the bullet.
2. My bullet was about .001 SMALLER than my bore.
This thing is turning into a real shooter, at 100 yds I was getting 5-shot groups less than 2" when I could see the target.
Will probably not slug anymore as long as I have cerrosafe.