Thought I'd apply Barlow's formula to the subject barrels



The chambers are 2 5/8" and the wall thickness at the end of the chamber was .119". Estimating the OD is difficult so did ID + wall thickness X 2. This does not include the brazed flats which obviously provide significant additional metal/strength to the breech, but the barrel blew out laterally.

SO 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.

Burst pressure = 2 x 54000 x .119" divided by 1.053"

And the number is only 12,205 psi?!?! What am I doing wrong?

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