Not being a mindless automaton, I would not be increasing the powder charge to maintain a constant peak pressure (as per standard practice) as the bullet weight decreases, since that would be the opposite of my goal. I do have some slight understanding of reduced loads (just skip to the last post in the thread for the whole story):
http://www.thehighroad.org/showthread.php?t=700533
Hornady claims XTPs will expand down to 800 fps. Maybe it's true. I'd be looking to get in the 800-900 fps range. I'd agree that the 110 grain XTPs are not that much worse to shoot at this velocity than the .380 size.
But I figured there must be something I was missing here, other than the fact that there is no 85 grain XTP (not sure how I got that idea), and so there is. RC's point about neck tension is well taken. OTOH, if they hold together at all, it would be possible to crimp over the shoulder or base of the ogive, so at least the .380 bullets wouldn't pull in a revolver.
My next bright idea was that there are 75 grain and 100 grain .359 cast wadcutters available, which would make a neat, painful hole without need for expansion. Finally it occurred to me that in the "things I already have" category are some 125 grain plated TCFP .359 bullets. Not quite as light as I wanted, but this evening loaded a half-box of those over 3 grains of Red Dot with the bullets upside down, to give the rare boat-tailed wadcutter bullet
lightly crimped over the base of the bullet. Not a good shape for fast reloads, but that's not a concern. I hope to get to the range on Sunday to give them a try at paper.
The point of all this is to make something that a skinny 15 year old girl who doesn't like practicing might shoot in an emergency without excessive muzzle jump or hearing damage. While there would be much more effective SD options, I have in mind the old joke about .22s: "You may only be shot with a .22, but you're still getting shot."
