Originally Posted by
P Flados
FYI, Out of curiosity, I ran some quick numbers.
The breech thrust on a 44-40 at the rated 16,000 psi is going to be around 2,300 lbs.
The breech thrust on a 38 Sp +P at the rated 18,500 psi is going to be around 1,860 lbs.
It would take a chamber pressure of 23,000 psi for a 38 Sp reloaded round to approach the breech thrust of a 44-40.
If a breech face is too soft, a very high pressure round can eventually peen over some material at the firing pin hole. However even mild steels have a yield strength way more than the 18,500 psi of a 38 Sp +P.
If you are using a modern 0.357" blank, it should be made of a good heat treated steel. The actual barrel should handle 357 magnum type pressures as far as hoop stress.