There's something I don't think I was clear enough on: a LOT of the 38/38+P JHPs out there are...well, they range from "mediocre" to "horrible".
I named the specific loads I'm willing to trust based on the data I've seen so far.
The jury is still out in my mind on the RBCDs. I'm not sure they're expanding/fragmenting in 38Spl; if they're not, then...well basically, unless there's a need to defeat heavy bone, you really don't gain anything driving a non-expanding round faster until you hit the hydrostatic shock point somewhere past 2,000fps. From about 900fps up, you're just drilling holes with hardcasts or other non-expanding rounds and IF that's what the RBCDs prove to be...then 1,700 and 300+ ft/lbs isn't doing anything for ya.
What speed gets you is hollowpoint expansion (or in the case of the E-FMJ or Pow'R'Ball, expansion by a mechanism other than hollowpoint). Getting jacketed hollows to open below 1,000fps is a bit of a trick; Winchester's aforementioned 130 Supreme gets there with a BIG hollowpoint cavity. The Gold Dot uses a good basic design (jacket is also on the thin side as it's electroplated) while the all-lead 158s work by not running a jacket at all.
If the unjacketed soft-lead hollowpoints are driven at 357 velocities or out of a 38Spl carbine, they'll do a classic "overspeed failure" - expand, and then shed the nosecone completely, dropping back down to caliber width or close to it. So this design still works for slower rounds around 800-900fps, such as the 44Spl and 45LC.
Where else speed matters: the guys trying to stop big deer by breaking the shoulders run hardcast non-expanding as fast as it can go. Hence we see 45LC+P loads involving 300+ grain hardcast @ 1,300fps+, or 454Casulls even hotter. BUT if you're going to do heart/lung shots, 250grain @ 900 - 1,000fps at pressures that won't blow up an early Colt Peacemaker are perfectly reasonable and can make the SAME stop with the same shot that a wild-child 454 400grainer @ 1,500fps can do. Either way, you're drilling a hole with no serious hydrostatic shock effects.
And that's why I'm wary about the big energy numbers behind the RBCD concept. A 158 lead hollowpoint at 900fps can defeat any bone in the human body 'cept maybe the pelvis, which will stop an RBCD featherweight flyer cold too. The 158 will do so regardless of whether or not it expands.
Big energy doesn't always do anything useful.
