Original proof for black powder between 1875 and 1887. Sleeved and then re-proved for 2 1/2" cartridges at 3 tons per square inch service pressure sometime between 1954 and 1989. If it has had the chambers lengthened at some time since I wouldn't use anything in it as it will have been materially weakened. If as suspected it has gone to 3 inches then just think where the extra metal has been honed out from; right up against where the sleeving joint is. If in any doubt then please, please have it checked before firing. Lagopus.....
