My Uberti .45 SAA Regulator (4.75” barrel) will sometimes leave lead stuck to the forcing cone - not just in the forcing cone but also on the face of the forcing cone. I have to chip the lead off with a nylon pick, even after letting Hoppes #9 sit on it for two days.
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I slugged the muzzle of the barrel, and measured a bore diameter between 0.4496” and 0.4507”, depending on which grooves I was measuring. The cylinder throats have a snug fit with a bullet measuring 0.4527” and a 0.4550” bullet does not fit.
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I shot about 100 rounds of 255 grain SWC with a modified Felix lube, moving between 750-800fps. The alloy was a 50/50 mix of COWW and SOWW, and fluxed with Root Kill to get about 0.2% Cu in there just for kicks. Powder was Ramshot True Blue. My sizing plug measures at 0.4496”.
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I do not get barrel leading with 96-2-2 alloy or harder, but I need at least 94-4-2 in order to keep my forcing cone clean after 50 rounds going 775fps. This 50/50 alloy is the only stuff that put lead in the barrel. Based on what I’ve read, I thought my 50/50 alloy would be fine, but I guess not.
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My biggest surprise is the 0.0011” roundness error in my barrel. Accuracy with this pistol is better than me, and sometimes I get 3 out of 5 holes touching each other at 15 yards.