Question: can my remington 1100 shoot 3 inch shells

Answer: Yes, The 11-87 incorporates a self-compensating gas system design, which allows the gun to operate with every type of load, from light 2 3⁄4'' to 3'' Magnum shells without any shooter adjustments. It is manufactured in two different gauges: 20 and 12, and both will cycle 2 3⁄4'' and 3'' shells.