Was testing a 38 spl vs 380 vs 25 ACP yesterday, for penetration thru two standard grade spruce 2x6s, saw your thread, thought I'd pass this 2 cents along.
Remingon 38 spl 125 gr SJHP. Stout recoil. Penetration -1/2" - very shallow.
Winchester 38 spl 130 gr fmj. Softer, yet snappy recoil, Penetration - thru the first 2x6 and 1/4" into the second 2x6.
Remington .380 95 gr fmj. Mild recoil. Penetration - made thru both 2x6s.
Winchester 50 gr fmj. Very light recoil. Penetration - 1 and half 2x6s.
After all this, shot a 45 ACP, went thru the two 2x6s, it broke both 2x6s in half and left a large splintered exit cavity.
The specialty HP ammo needs to hit a soft area to be effective: heavy clothing, fat, cartiledge, bone, leather belt, hard cover, etc can defeat it.
If my wife needs a 38 spl J-frame, would load it with standard pressure 158 fmj or solid lead round nose or wadcutter.
Pics below, handguns used in test: S&W 38 spl J-frame M438, 380 cal Sig P238, 25 cal Walther PPK, and 45 cal SA Micro 1911 at top. Barrels 3" or less.