The Mark 4 System employs a slot and spline design, and comes in 1-Piece and 2-Piece configurations. Mark 4 Bases accept Mark 4 Rings, Cross-Slot Rings, and QRW/PRW Rings.
For:
- Winchester 70 Long Action Non Express
- Winchester 670 Long Action Non Express
- Winchester 770 Long Action Non Express
- Winchester 70A Long Action Non Express
- Winchester 70 Short Action Non Express
- Winchester 670 Short Action Non Express
- Winchester 770 Short Action Non Express
- Winchester 70A Short Action Non Express