Powder Fouling in 357 Sig Chamber

[calvon]

I'm shooting cast bullets in a P229 357 Sig. After twenty or thirty shots powder fouling builds up in the shoulder area of the chamber to the point that a loaded round won't go all the way in. The only cure is to field strip and scrub the fouling out. I have used Win AA473 (no longer made), AA#9, AA#7, and RamShot TrueBlue. All foul about equally. Is there a super clean powder that's compatible with this caliber?

I also have a .40 S&W barrel for this gun. I don't have the fouling problems shooting the same powders in this barrel

[PaulS]

It probably isn't powder fouling. You are likely experiencing fouling caused by oxidized bullet lube or a mixture of lube and lead building up just in front of the neck of the case. Use a different lube or try using jacketed ammo to see if you have the same problem.

PaulS