My grandfather was a poor immigrant from Sweden to the Alaskan Gold rush, where he bought and Iver Johnson break top hammerless 38sw.
Inspired by our family heirloom worth $35, my brother and I started collecting 38sw pistols starting in 1963.
When the action stretched on a break top from shooting 38 Super +P loads, I complained to my father that I had used too much pressure.
My father was high powered chief engineer with 150 engineers and draftsmen under him. He has ~ 36 gun related patents.
My father yelled at me ~~ Pressure has nothing to do with it directly. It is friction of the bullet in the barrel and recoil acceleration on 1/2 the mass of the barrel.~~
It took me a while to get my more average engineer brain around that statement, but I think I have got it now.
So now in break tops [so the latch pin capture hole in sheet metal will not stretch into an oblong shape] I shoot 1 gr Bullseye and a soft lead bullet or maybe 2 gr Unique.
But in Colt revolver with the post 1907 Police positive lock up system, I am shooting the equivalent of 9mm+P handloads in 38 S&W.
CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.
1) Colt 38 S&W Police Positive 38 made in 1911 20.5 ounces 4" barrel
a) 4.5 gr Unique 115 Win JHP, obnoxious recoil, tiny pierce in primer
b) 6.4 gr Power Pistol 115 gr JHP WIN 1.299" recoil painful