Mossberg 500 20 Gauge Magazine Rail

Designed to fit under a 20mm diameter magazine tube, ie 20 gauge shotgun. Interior diameter is a little bigger to accomodate a thin layer of cork board material to prevent slippage. Use medium nylon zip ties to secure to the magazine tube.

Thanks to Hinfa for the "Crosman 1377 Picatinny rail" which I used to get the base rail dimensions from.