Well if a 3 ton (6720 psi) crusher service pressure is equivelent to "10,730 psi (service)" that means it gained 4,010 psi (+60%) in the conversion. I for one am not sure we have all the last words on this subject. Personally I believe the 8960 psi figure is much more realistic & on those guns proofed to 1 1/8oz or 3ton I will stay below 9,000 psi.
Miller, I don't believe I equated a 3 ton service pressure to 10,730 psi. The Birmingham Proof house DID equate a 650 bar service pressure to 10,730 psi. I seem to recall that proof and service pressure did not change when the Brits converted from the "tons" markings to bars--but I can't verify that. Probably time that I check with the proof house on the "tons" guns and see what they have to say.
But I certainly agree with staying below 9,000 psi on older Brit guns. That's what I do myself, with my Scott-made Army & Navy guns, from the 1930's.
Last edited by L. Brown; 04/03/07 09:42 AM.
