My Father, Grandfather and Uncles were all convinced that those Damascus and Twist barrel warnings were just an attempt by the manufacturers to scare consumers into buying a new gun. I know my Father's 1896-vintage AE-Grade Remington Hammerless Double and my Grandfather's 1890-vintage PH-Grade Parker Bros. double both digested many, many, cases of Super-X and Federal Hi-Power shells over their lifetimes. Dad's AE-Grade is still looking fine in my gunroom. He shot it up to when he quit hunting in 1988 after he turned 81.
For two or three decades now I've heard this moaning over modern "SAAMI" spec ammunition. But, I've never seen any definitive information on what the pressure specs were for earlier nitro powder loads like say 3 1/4 drams of DuPont (or Schultze, or E.C., or Hazard, etc.) bulk smokeless powder and 1 1/4 ounce of shot, or say 26 grains of Infallible (or Ballistite, etc.) dense smokeless powder and 1 1/4 ounces of shot??? I have an early Western Cartridge Co. brochure on their Super-X load, and it says with their new progressive burning powder they are achieving this level of performance at lower pressures. But, I think that means a 3 3/4 dram equiv. load and 1 1/4 ounce of shot, while with the older bulk smokeless powders the heaviest 12-gauge loads offered were 3 1/2 dram.
Researcher, can't help you with the pressure specs on those "pre-modern" smokeless loads. However, I did save a discussion of proof and service pressures on old, short chambered guns--courtesy of Greg Tag, going back quite a few years. Greg quotes Calvin Goddard in the May-June issue of "Army Ordnance", as reporting that Hunter Arms proofed its short 12ga guns at 14,300 psi. Parker's short 12's had a service pressure of 9500 psi, and both Parker and Ithaca proofed at about 15,000 psi. Given the date of that article, I think the psi figures are more likely to be LUP, since crushers were still being used back then. So, using the "ballpark" psi to LUP conversion of +1,000, we get a service pressure of around 10,500 psi for those guns. That figure is further substantiated by Arthur Curtis in a 2-part article in the American Rifleman, also in the 30's, addressing the issue of long shells in short chambers. Curtis, who had worked in the firearms industry for about 40 years and was with Marlin at the time he wrote the article, suggested that the "modern" loads increased pressure by about 1,000 psi. That fits quite nicely, because it would mean they were at the current SAAMI 12ga service pressure standard of 11,500 psi.
Like your father and grandfather, back in the "day"--although my day isn't as long ago as theirs--I shot numerous high brass 1 1/8 oz pheasant loads through a pre-war Sauer and an Ithaca Flues, both 16's and both of which had had the chambers lengthened. Can't say that it did anything bad to either of those guns, although I would tend to err on the side of caution today, knowing what I now know (much of which I've learned here).
