Slim: Your slugs were lovely to work with. I cast some of the Lymans up with 20:1 alloy. Ran 10 of mine and 10 of yours through the .452 lubrisizer die with SPG. In WW cases with CCI 350 primers, I charged each with a 2.2 CC Lee scoop of Goex FFg, about 33.5 grains. I didn't drop tube the loads, just poured in the powder and seated the bullets. Both the Lee PRS and the Lyman have the crimping groove in the same spot. I just got back from the range, shooting the new Marlin cheapie carbine in .45 Colt for the first time (also did some barrel break in with the .416 Taylor and Hornady 400-grain RNs, but that's another era).
In my very unscientific test, I put five rounds through the rifle as fast as I could, then sat down and shot five off the bench, then pulled the lever and breech block for inspection and cleaning. After 10 rounds with the Lyman ( and lousy accuracy--7 inches or more at 50 yards) it took three patches soaked with Birchwood Casey BP solvent to clean the barrel, with traces of fouling left at the muzzle. With the PRS bullet, same drill, the bore came clean in two passes with the patches, with no fouling at the muzzle. Visually, the bore looked dirtier after 10 rounds with the Lyman slug than it did with 10 rounds of the PRS. And the PRS grouped in four inches. That's a lot better than the Lyman, but not nearly what I would expect with one of my favorite smokeless loads of 7 grains Red Dot under the Lee 255RF.
However, I must say that the days when I can accurately shoot a black bull at 50 yards with open rear and bead front are about over.
To sum up, based on an admittedly small sample, I think the PRS is clearly the superior bullet for shooting BP loads in a .45 Colt Marlin carbine, both in terms of accuracy and in terms of keeping fouling to a minimum. Darned good design, Slim, and the folks at Lee are knotheads if they don't catalog this one.
