I just measured my 26-in barreled 1100, there's 13-inches from the mag cap to the end of barrel. If you do the rough math: 5 x 2.75 = 13.75. Of course, actual 2-3/4" 12-ga shells are shorter than 2-3/4", more like less than 2 3/8". 5 x 2-3/8 = 11-7/8" YMMV