This Army Ordnance taken from the 1925 British Rules of Proof show a mean working pressure of the 2 7/8" 10ga factory loaded shel as being 11,200 with a maximum individual of 12,000. Mean proof pressures was 16,800 with individuals showing a max of 18,100 & minimum of 15,400. Pressures are also shown on this chart in tons. The tons shown are slightly rounded to equate to the pounds divided by the British Long ton of 2240 pounds. These figures would seem to fit in with actual PSI rather than the more commonly listed Crusher pressures of that day. The mean working pressure of factory loaded 2 5/8" 12ga shells is given as 9500 or 4�tons. This is what we would normally take as a "3 Ton" gun by the Crusher method.
I do not have any input as to what pressures Remington was proofing to in 1904.
