Well, I need to apologize for not having results yet.
I've been doing a lot of head scratching before actually getting off my can to load the lovely bullets that Skip sent. (I suppose better to do that than blow up a gun.) The bullets, as you can see, seat awful darn deep for a bullet of this weight. Naturally, this makes me loath to use any sort of data for most bullets of similar weight. The extrapolation is what's slowing me down: I'll get to where I'm sure that something's a good idea, and then sleep on it and re-think the whole thing.
The fact that the range is 35 miles by road from my house doesn't help - I want to be sure to load up a decent variety of loadings to take over there. Since I've been going through the same "I'll do this! Wait - maybe that's crazy . . . maybe I should do
that? Wait! What about
this?" process with each powder I've been considering, I've not been real efficient on this project.
Powders I'm considering, FWIW, are:
Unique (of course)
SR 7625 (Jessie turned me on to this stuff, and I've been amazed at how versatile it is)
SR 4756 (of course)
Power Pistol (it's done well by me)
2400
(and, last but not least)
Trail Boss.
You'll note that I don't have Bullseye listed. I just worry that it's too fast to safely get me the velocities that I'm after (which I've now modified to
830 fps from a 1 7/8" snub - I think I've decided against running these fast out of the .357s just because I already have good heavy penetrative bullet loads for those - the benefit I see in these sharp-edged little monsters is that, as friend LeVick notes far up-thread, these would make hellacious defensive bullets at low-ish velocities). I know that TB is mighty fast as well, but it's not
quite as fast and, well, I have a (possibly incorrect) belief that I'm okay with it as long as I'm not compressing the powder - it really does seem to be a pretty idiot-proof powder, at least with non-magnum primers.
I don't own any Red Dot, or else I'd be thinking strongly of it on the fast end as well. Green Dot . . . well, I've just had some weird results with it thoroughly leading bores at velocities that are a lot less than I'd ever expect, and so I'm leery of experimenting with it. I have found a couple of great Green Dot loadings (a wonderful +P .45 ACP 200-gr load and a fine 148-gr .38 Spl loading that's warm enough for practice but not as fast as what I'd consider a "defensive wadcutter" round), but - though Skip was most generous with the number of bullets he sent me - I don't feel as if I have so many that I want to risk a bunch of them fooling with Green Dot. It might work, but I'm guessing I'll do better with these other powders.
Truth be told, the powders that I've got the biggest hankering to use with these bullets are 7625, Power Pistol, 2400 and Trail Boss. Two in the middle, and one on either end of the .38 Special burn-rate curve.
I have to say a couple of words about the bullets that Skip sent, by the way.
You ever get a pizza that was made perfectly? Just the right amount of toppings, of the best quality, distributed perfectly over just the right amount of flawlessly flavored sauce with
precisely the right amount of top-level cheese, cooked just exactly the right amount of time at the right temperature? I've made a
lot of pizzas, and I've eaten a whole pile of them. I'm no expert. I can do a pretty good one, but I've for sure never made ones as perfect as a few that I've been fortunate enough to have run across. There aren't a whole lot of steps to making a pizza, but there are a LOT of
variables. Variables that only a master really knows how to control. And, really, I've seen that even master pie makers don't make a master pie anywhere near all the time.
Cast bullets are like pizzas - not a lot of steps involved, but a
lot of variables.
Every single bullet that Skip sent me was a masterwork. The hardness is beautiful. The lube is precisely placed (and I'd expect that it's a concoction that he's developed over the time he's been casting). The edges are so sharp that they look machined. The sprue cuts are nigh on invisible. And they're all the same, every one of them.
I've not gotten any of these out to the range yet, but I can tell you that I've gone into my component stash several times just to pull out one of Skip's bullets and sit it in my hand to contemplate it.
Almost seems a shame to shoot them.

Skip, thanks again: you
really know what you're doing!