Thanks Dan. One of these days I'm just going to take the plunge and try some round balls.
My plan was to go with a ball slightly over size, possibly using an unsized case if need be to prevent bulging the case mouth and to reduce the need for belling the case mouth. My thinking is that the slightly oversized ball will provide a bit more bearing surface when it swages down to fit the bore. More bearing surface should keep stripping down and help keep leading to a minimum.
That's my plan anyway.
I don't have much experience with raw lead down barrels, being disturbed and all that. Little bit of shooting retail lead bullets in various guns over the years, not much more than that until recent times. Began the excursion away from jacketed bullets in earnest back in '99, mostly with paper patch. My life continues down that tortured path. Dunno what I'm going to do with 2 lifetimes supply of jacketed bullets, but I'll figure it out.
Regarding your plan, I doubt you need to oversize the balls to increase bearing surface if the velocity is mild. Best guess starting geometry for lead is groove diameter + .001". The barrel on my Ruger is .430 in the groove. My limited experience says if you keep the loads mild, stripping won't be an issue. When the balls engage the rifling there is some swagging involved right there, so you'll get some bearing surface improvement. A single ball is light and not hampered much by inertia or prone to develop great pressure for a given charge.
I drove some of the balls from the .44 fairly hard a few times and they shot well. Now they were paper patched, but that does not infer resistance to stripping, but does mitigate leading completely.
I would not speculate about how much pressure you can put on them before leading presents, but I ran the patched balls up to around 1,800 fps without stripping. 25 yard groups ran about 2" offhand. My recollection is the balls weighed something over 100 grains, give or take, and when I used the double ball loads I used load data appropriate for that weight. They printed as two groups, one more or less to POA, the second at 10 o'clock and about 6-8" out. Dunno why that was so but they were very consistent in that.
