Called the Lucy adapter, this elegantly simple coupler is placed at the rear of your 20 gauge small frame, Lightweight 870 receiver, allowing the 12 gauge stock to then rigidly bolt to the 20 gauge Lightweight receiver. This greatly increases the options and availability of butt stocks for the 20 gauge shotgun. Mfg: Mesa Tactical Products, Inc.
Mesa Tactical Products, Inc. Lucy? Adapter For 20 Ga Shotguns (Rem 870)
$25.99
Vastly Expands Stock Mounting Options For a Light, Maneuverable Tactical 870