Many people question if there were ever any 3" 16 ga shotguns and cartridges ever made. I have a 3" cartridge, British made, and here's a shotgun that sold awhile back at Gavin Gardiner's auction with their description. "ARTHUR TURNER
A FINE 16-BORE (3-INCH) SIDELOCK EJECTOR GUN, NO. 12145
27-inch barrels with 3-inch chambers, about 1/2 and 3/4 choke borings, file-cut Churchill rib, mid extension, the frame, locks and gold numbered top lever with fine scroll engraving and retaining virtually all of its original hardening colour, the maker's name signed within a scrolling banner, gold lined cocking indicators, rolled edge trigger guard, 14 1/4-inch highly figured stock including chequered butt plate, 7lb. 4oz., nitro re-proof, in its canvas case with maker's label". Estimate was 5000-7000 pounds.