I believe the other "non-standard" 20 gauge 1100 barrel would be for a SPECIAL FIELD model. Also you would need to specify 2 3/4" or 3" Magnum...I don't think 3" magnum barrels fit 2 3/4" receivers...and then you need to know if your 20 gauge is a "small" frame or a "large" frame gun. I hope that helps more than it confuses things for you.
