Cause of Barrel Leading

First topic message reminder :

Hi all:  Years ago I used the Star 185 gr bullet with great success. I used 4.0gr Bullseye under them and crimped to .468. That gave me right around 750fps. They shot just as well as the Remington jacketed 185 SWC. I had no leading at all with them the whole summer I used them. Then all of a sudden the accuracy went down the tube. I checked and the barrel was severely leaded. I cleaned it all out and shot them again. Within 100 rounds, the accuracy was gone again. This happened several times in a row, so I quit using them. Recently I came across a good deal on 8000 of them. I have cleaned the black lube off some of them and tumble lubed them with 45-45-10. Same load, same crimp. I shot around 200 of the tumble lubed ones from a freshly cleaned barrel (different guns-different barrels) and checked the barrel. Severe leading again. I then tried some of the bullets with the original black lube- same results with two different guns. I have tried dropping the powder charge down as far as 3.7gr. BE and crimp down to .466. I do not know what is causing this. Does anybody have any ideas why this is happening and any suggestions on what I might try to fix this problem as I would really like to use these bullets. I know that somebody on here has some idea of what is causing this. Thank you in advance.
Paul

Firebrushing ( for heavy or stubborn leading) is using a cigar lighter or propane torch on low conical flame. While holding the barrel in your hand, run the flame up for 5 seconds then brush. The barrel doesn't get hot and the heat flux through the deposit is what beaks it loose from the substrate. 

Leading sppears as tool chatter or spots in the barrel that are visible after you have already cleaned it. Some is always there and its normal.

Kroil works wonders for cleaning especially for rifles where you can't firebrush.

Good luck

[url=/u2251]Caster3845[/url]:
1) bullets too small for groove diameter. Order larger bullets
2) bad lubricant, but I don't think this is your issue
3) bullets too soft for high speed use, but I don't think this is your issue.
Therefore, I would try some tumble-lubed in Lee Liquid Alox and learn about powder-coating your own bullets.
45/45/10 had LLA in it, but it also has wax. Pure LLA is very tenacious and eliminated all or almost all leading in by guns when I have issues with commercial lead bullets.