I am starting a program of testing the accuracy of the same boolits when tumble lubed as opposed to powder coated. I am going to use the 327, the 38 and the 44 special to test, simply because I have 50 new cases of each, and accurate revolvers to try them in. ( I could add 32-20: I've a bunch of new brass, but neither of my 32-20 revolvers has proven to be very accurate in the past.) I am going to cast up a hundred bullets of each, visually sort, and then load up 25 after powder coating and 25 after tumble lubing in old BLL. Each boolit will be loaded into new brass from the same lot. The 38 will be Winchester, while the 327 and the 44 Special will both be Star Line. The 38 will be the MP Mold version of the 358-429 HP, ~158 grains. The 44 Special will be the MP 432-423 210 grain boolit and the 327 will be the 314-640 100 grain HP. I will not be weight sorting boolits or weighing charges, but will be loading each cartridge with normal, reasonable care.
I will fire five five shot groups from revolvers of known accuracy at 25 yards, each group on a new target. I will alternate, firing five shots of TL boolited ammo, then 5 of the PC boolits. I will measure the groups and see if I can determine if powder coating or tumble lubing is more accurate for me.
Today, I tried to run a test of the 38 ammo, but ran into a few snags. The lighting conditions were affecting my shooting. We had scattered high clouds and when the sky cleared, my shots were going high. When the sun went behind a cloud, my shots went lower. And my bags were sliding on the bench initially. I had to move over to an older, more weather beaten, bench to resolve that problem. Consequently. I only ended up with 4 groups each, not five, and there was vertical stringing present in some groups that I am sure was the result of changes in the lighting. So I will have to reshoot this test. Just at a glance, I don't see a significant difference. However, this battle has just begun and I suspect any resulting difference will be in millimeters, not inches. It will keep me busy for the next month or so.