Leading Problem in Vaquero .45Colt

[Hylander]

I am getting leading around the edge of the forcing cone and in the first inch of the barrel.
What would be causing this.
I have only fired 50 rd.
My Load:
New Starline Brass
200gr. Bear Creek .452, Moly coated,  hardness 13
7.5 and 8.0 gr. Unique
OCL 1.585
Win. Primer

My Bore is .451
My Throats are .451

What do I need to change

[El Paso Pete]

I had the same problem in my .44 mag Vaquero using moly coated bullets.  I was spending all much as much time with my Lewis Lead Remover as I was shootin.  I switched over to cast bullets with real lube grooves and lube and the problem when away.  If your shooting a .45 you might want to get some of these a feller got up on Ebay or get some Black Dawg bullets.  They're for black powder but work fine with smokeless too. 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7141747083&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

Another thing you could try if ya want to see if the moly coated bullets are the problem, is put a glob of Crisco on each bullet before you load it the cylinder.