What does location of leading say

[walnutred]

about the cause of the leading? I am trying to develop cast loads for a CZ82, 9x18. Mold is Lee 95gn RN as cast with LLA for lube. The loads I have been using are top in 380 loads, so they should not be hot for the 9x18. The lead is straight wheel weights.

I notice leading streak about 3/4" long in the middle of the barrel. What should this tell me about the cause of the leading? Wouldn't think gas cutting would be closer to the chamber? I would try a conventional lube but have not been able to find a sizing die for this caliber.

[fourarmed]

In the NRA Cast bullet book, E. H. Harrison states that leading near the muzzle generally indicates a failure of lubrication, while leading near the breech usually indicates the use of a powder with too fast a burning rate.

[jonk]

I'm not sure I believe this, but the CZ 82 has polyaganol rifling which they SAY is a no no with cast....but again, i'm not sure I believe them, other than to agree that that SHALLOW nearly non existant rifling could fill up with lead quickly if you don't do your part.

[lovedogs]

I'm no expert but to me it sounds like you have a rough spot or a dimension problem in just that spot. I've seen this in barrels that had an uneven spot, like a ripple or wavy surface possibly caused by a glitch in the rifling process, such as a button chattered as it was drawn through. I once lapped such a spot out of a Contender barrel and it smoothed up and was a great shooter.

[walnutred]

A suggestion that was made on another board was that I could have copper fouling at that spot. I am going to try a copper solvent this weekend and see what happens. That theory would line up with the rough bore theory.

[crowbeaner]

I'd polish the rough spot with some Flitz on a patch. Then I'd add some tin to your mix to firm the alloy just a bit. I had a Marlin that only leaded 1/2 way down the barrel. I determined that rough rifling and consequent copper fouling were to blame. After Flitz and elbow grease the problem subsided.