I tested PP in 38 Spl with 158LSWCs
a couple of years ago. Power Pistol is one of the 'velocity champs' in 38 Special for me.
I set it aside after testing it with the GDSB 135-gr JHP, two different 140LTCs, and 158LSWCs--but for a reason that really is irrelevant here: I was seeking a reload that would replicate the recoil of the Speer 38+P 135-gr. factory PD Ammo, and then later I tested it to see how it compared to a typical "FBI load" ammo. (For the Speer 135-gr. recipes, the recoil was noticeably 'harder' and 'fuller'; AA#5 and Ramshot's True Blue are the best matches.)
Alliant currently shows a 38+P max charge weight of 6.0 gr. under a Speer 158LSWC-HP; my 6.0-gr. test under a locally-branded 158LSWC showed 839 fps, 14 SD from a 2&1/8" barrel (S&W 640). Run out of a 3" barrel (S&W M60), it ran 891 fps, 12 SD. Unfortunately, I haven't run it yet from a 4" barrel; but, it looks to me like one could add on about 50 fps to the 3" results--so, perhaps 950 fps on a good day. If the recipe were bumped slightly to reach 38-CIP pressure max, 950 is easily obtainable. IMO. That puts it just beyond using swaged bullets (e.g., Speer 158LSWC-HP) without significant leading, I think, but should be just fine with BHN 11-14 or so bullets.
These chrono tests were ten shots--i.e., statistically significant--and were shot on an overcast day with the temp in the mid-seventies. The typical factory ammo (Rem new, or Georgia Arms reloads) for the "FBI load" at current max pressures does well to break 800 or a few fps over.
FWIW, idahoglock36, 5.2 gr. produced 741 fps from the 2" 640 and 781 fps from the 3" M60.
Unfortunately, I transcribed no other comments from the range notes into the database so I have no comments on burn, etc--only that I remember it as "flashy," and that full-hard recoil. IMO, it's worth trying and working with in 38 Special. I may run some more tests with it this summer.
Jim H.