I have a Lipsey’s (Ruger) .44 Special Flattop and I’m having quite a time trying to solve my leading issues. The gun slugs at .4295 and cylinder throats are a uniform .432. I’ve tried both the Lyman 429421 sized to .430 and .431 (the .431 requiring just a slight push to pass through the throats) and Accurate Molds’ AM432250K sized to .431. Two alloys, one is straight COWW and the other consisting of 10 lbs COWW, 1 lb Linotype, and 2 oz tin. I’ve tried several loads using Unique, Universal Clays, and Titegroup. I have not tried 2400 yet as I’m not looking for hunting loads for this gun, just casual shooting. Loads ranged from mild to about as much as I want for range fun. 6.8 of Unique “feels” about where I want to be and I felt should be enough to provide sufficient obturation with my alloys. Everything I have tried has left significant lead deposits in the barrel from the throat forward about 1-2”. I have to use a piece of copper chore boy over a mop with solvent to scrub it out. When cleaning with a tight patch, I do detect some constriction at the front sight but surprisingly, none at the frame where the barrel threads in. I had planned to fire lap the gun but given the lack of thread constriction, I’m not sure that’s going to help me. For lube, I'm using Thompson's Blue Angel but just received some White Label Carnauba Blue I'm going to try as soon as the replacement die retention nut shows up for my Lyman lube sizer (my other exercise in frustration).
My next step is to have the forcing cone re-cut and polished but there’s an 18-month wait at my local smith who I trust to do the job right. I’m hoping maybe someone here, possibly another flattop owner has encountered and dealt with this issue and might have a suggestion for something else to try while I wait for the call from my gunsmith.
Thanks in advance!