John: Buck Hamlin was given an extremely well-used damascus barrel Lefever with a burst right barrel just past the forend tip. The barrel wall thickness at the rupture point was .010”, and the chamber was 2 5/8”.
With the intent to rupture the left barrel, Buck measured the bore diameter and started his effort with a box of 2 3/4” 1 5/8 oz. short magnums. After 25 shells the left barrel had no change in bore diameter. He then lengthened the chamber to 3”, and following 25 1 7/8 oz. magnums (lead #2 and BB) there was still no change in bore diameter.
Buck then lengthened the chamber to 3 1/2” and used 3 1/2” 2 1/4 oz. lead turkey loads. The left barrel blew after only a few shots. The wall thickness at the rupture point, which was almost aligned with the bursting point of the right side tube, also measured .010”.
That is of course not to say any
other gun would survive that trial.
In the Birmingham Proof House Trial reported in 1891, there was not attempt to measure pressures of the increasing loads used.
IF the pressure increase had been linear, the pressure at Phase 1 failure for the first place barrel would have been 4.66 X 11,500 (piezoelectric transducer) psi =
53,590 psi.
The pressure at Phase 2 failure for the five first place barrels would have been 12.5 X 11,500 psi =
143,750 psi, an extraordinary number.
It must be kept in mind that these were specially bored 30" barrels without chambers and with wall thickness of .150” at 3”, .092” at 6”, .048” at 12” and Minimal Wall Thickness of .035” at 21”.
https://docs.google.com/document/d/1cvqRzkg0wEjhAAcFWr8gFi7aPFRsSIJ_hahfDxmrNAU/edit Mark Twain
“It is better to be careful 100 times than to get killed once.”
I've given all my vintage Smiths to Cracker Barrel at jOe's suggestion
