I thought Leading was possible to avoid in .38 Special and even some ways above it's normal range of Velocities by correct choices of Bullet Lube even if using pure Lead Bullets.
Granted...much of this History for expanding Bullets appears to have ended up having to do with ferocious accelerations in short Barreled Revolvers...and, to unusually high fps, where Leading became an issue...which, I suppose would not be a problem in a longer Barrel attaining the same fps, less ferociously.
Jacketed Bullets I believe need quite higher pressures behind them, and strain the Revolver more because of it, than do Lead or Lead Alloy ones of the same weight, for attaining the same fps.
If memory serves, FPS for 158 Grn RNL .38 Special in 1898, was 950, with 3f Black Powder behind it...but, I presume a six inch Barrel.
I have tried finding LSWC 158 Grn Factory Ammo, or, just the Bullets...to no avail.
Anyway...I've been brooding on what Bullet/fps/Cartridge to be considering (even if respecively,)for the (few, if cherished) S&W .38 Special Revolvers I have and may sometimes Carry.
Barrel Lengths are 2, 3, 4, 5 and 6.
Only a couple of which would be imagined to be 'rated' for +P.
My thoughts led to recalling the old 'Double Ball' idea...
And, also, for a pure Lead, widely Hollow Nose, 158-ish Grn Bullet...Round-Hollow-Nose would even be fine, I'm sure...or widely-Hollow-Nose-Semi-Wad...or even a Hollow-front-Wadcutter.
And, if with pressures say, at or below 20,000 psi, which any S&W .38 Special regardless of age ought to be happy with now and then, if with the right Powder, if that's enough for the Bullet in question to be going 650-ish from a Snubby, or 950-ish out of a 6 inch Barrel length, should such a Pure Lead Bullet not behave well-enough in expanding?
Heck...I could get these fps out of these Revolvers with 3f BP for that matter...though I am sure various Smokeless Powders once decided, should be able to do better, with out over-pressuring things.
Brooding...musing...learning...
Thanks..!