ed: would you please share the source of the Krupp 90,000 psi bulging report? The 5X proof pressure? Which is not part of that Trapshooters.com thread to which I contributed. Tom Roster blew an 870 barrel at 55,000 psi BTW.
Krupp Fluss Stahl (Homogeneous Fluid Steel) was introduced about 1890 and I have found no published data regarding tensile strength, but composition suggests it was similar to AISI 1045 which would have a standard tensile strength of 85,000 - 90,000 psi
Krupp Nickel Steel patented in 1890 does have published strength at 92,500 psi
https://www.doublegunshop.com/forum...p;Board=1&main=13559&type=thread Dennis Potter contributed a Krupp Essen barrel segment to my tensile strength study. Unfortunately, it was from an unknown gun and DOM. I did not do a composition analysis, but the tensile strength was 113,000 psi
Tensile strength is only part of the pressure cylinder bursting formula however
Barlow's formula P = 2 x S x t / D
P=Bursting pressure in psi.
S=Tensile strength of material in tube wall.
t=Wall thickness in inches.
D=Outside diameter in inches.
Burrard used the Alger Burst Formula
Burst pressure = Ultimate tensile strength x 3(OD – ID) / OD + 2xID
Neither work for an unobstructed shotgun barrel ie. open at one end.
