Good attempt at not answering, but not good enough. 20K was just a nice round figure, make that ANY pressure you like, suit yourself.
The actual question was, if you sleeve the original chamber, what will be the difference in how much pressure it will hold. For that matter how much difference will there be in the amount of pressure required to Bulge a chamber assuming one of chopper lump & the other of mono-block construction, both having equal wall thicknesses.
It appears to me you are trying to condemn sleeving on a safety factor, If this is correct I would like to see factual figures which bear this pout.
20K may be a nice round number, but it ignores the reality of proof pressures. Standard English proof is 850 BAR, or, roughly, 12,328PSI. Note that there are a substantial number of old English guns, sleeved and otherwise, that are failing proof at this level. This has been going on since the proof house revised and updated their work to be totally in compliance with the most recent Brussels Convention.
There is a higher level of proof available, 1100BAR, but, Im not sure how often it is specified and if people regularly subject older double guns to it. This is roughly equivalent to 15954PSI.
The only safety connection I have tried to raise is that sleeved barrels are rejected for reproof in France. France never found itself outside the rules from the Brussels Convention, and, standard proof, about all that is left today, is 1250BAR. That is around 18,000psi. As to whether this is a concern or not is likely up to the user of a sleeved gun.
As noted, I am not that guy. But, I based that decision on what I have seen, and, there was a lot more bad sleeving then good when I was looking at English guns of a certain age. I dont do that anymore. The English thing is completely behind me, for reasons other than sleeving, by the way.
I have never been tempted by a sleeved gun.
Do you honestly believe that we can compare a monoblock and a set of chopperlump trousers, without regard to age or identity of steel, or identity of method used to construct the trousers, and come to a meaningful comparison of anything, based just on the comparison of the dimensions of each?
I have my doubts. You, can believe anything you want.
Do, however, indulge me, if you would. Is there a reason, in your opinion, to seek out a sleeved gun of any make, that goes beyond it being cheap, or, other guys own them?
Because, I havent seen a reason that goes beyond those two.
Best,
Ted
