I have a Stevens Model 335 Double 12 that was made according to serial number between 1910-1916, all major parts same number. Does anyone know if these shotguns had a 2 1/2" or a 2 3/4" chamber. Double locks up tighter than a tick on a hound, barrels have been cut to 20 1/4", but done professionally. It has a nice patina on metal, good bores, wood good except for a small crack by tang, and functions 100%. A friend who is into old doubles asked me and I advised the 2 3/4" went in without any problem. He advised that was normal. Impossible to measure. Don't do any serious hard shooting with it, mostly light trap loads and keep two in the chambers for home defense (no kids around-unloaded when grandkids come). Nice old double-miles above in quality to some of the modern short double shotguns on the market. Bought it for the 'sawed off' feature, although probably would have snagged it anyway.