Fits:
Cooey 60 & 600
H&R 65, 165, 150 & 151 auto
H&R 250, 251, 264, 265, 365, 450 & 550
H&R 755, 765, 852 & 865
Krag
Marlin A1 & 50
Marlin 39A round barrel
Marlin 88, 89, 98, 80, 81 & 980
Mossberg 25, 26, 42, 46M, 140, 142 & 146
Mossberg 45-46 with 3/4" barrels
Mossberg 320, 340, 342, 620, 680, 695 & 800
Mossberg 50, 51, 151, 152, 350 & 352
Savage 10, 11, 12, 34, 341, 510, 511, 512 & 521T
Savage 12A
Savage 121 with 3/8" & 13/16" barrels
Savage 33, 41, 5135, 513T & 514
Savage 3, 4, 5, 6, 7, 19, 23, 40, 45 & 219
Stevens 26, 53, 56, 66, 57, 76, 4171/2 & 762
Savage 416, 417, 418 & 4181/2
Stevens-Springfield 83, 85, 87 & 872
Winchester 03, 63 & 42
Winchester 52 with same hole spacing
Winchester 52 with different hole spacing
Winchester 57, 69, 69A, 72, 47, 74, 77, 75 Sporter & 75 Target
Winchester 61 round & octagon barrel

Krag & Marlin 39A require drilling & tapping
Savage may require gunsmithing