Hi Bob, yes should work on both. The rail installs via the included set screws into the Mossberg factory mounting holes. Crafted from lightweight aluminum, the rail is 5.4 inches in length and 1.4 ounces in weight. Note that pre-1997 Mossberg shotguns do not come with factory mounting holes. For installation on guns without the appropriate mounting holes, we recommend consultation with an experienced gunsmith. SCREW SIZE Manufactured prior to 1997 is 6-48 Manufactured after 1997 is 8-40 (included with this product)

A Mil-Spec 1913 Picatinny Rail will fit both without issue Bob.

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Other models would use this picatinny mount amazon.com/Mossberg-Shotgun-Picatinny-Rail-Mount/dp/B00ME8SZFS/ref=pd_sbs_200_1?_encoding=UTF8&pd_rd_i=B00ME8SZFS&pd_rd_r=C5083E1FBRP1VHDPS4AW&pd_rd_w=z0qIt&pd_rd_wg=zIoL0&psc=1&refRID=C5083E1FBRP1VHDPS4AW

The GGG-1074 is for Late Model Post 1997 models though