I've been shooting Bear Creek bullets almost exclusively for a few years in CAS. I found them to be the only bullet I ever used in a 45Colt SAA that did not lead the barrel. Most cast bullets lead a Colt because the chamber dimensions are still Black Powder, and the barrel is now 451. The chamber throats are about 457, and the blow-by burns the lead bullet base causing leading. The Moly bullets don't lead at all. I use them also in my Uberti Yellowboy in 44-40, with no leading and easy cleaning. The only problem I have with them is trying to pick them out of the box when reloading cartridges, they are so slippery! Tried them on the 45-70 with smokeless loads, they worked fine, haven't tried them yet with Black Powder to see how they handle heavy fouling..