Winchester Model 1400 Mk II Deer-Slug 12 Gauge Semi-Auto Shotgun, 22.5" Barrel, 2 3/4" Chamber, Cylinder Bore, Rifle Sights (1971–72)
This Winchester Model 1400 Mk II Deer-Slug is a purpose-built 12 gauge semi-automatic from the early 1970s, featuring a 22.5-inch smoothbore slug barrel with a fixed cylinder choke and open rifle sights. It is chambered for 2 3/4" shells and configured with a 2+1 tubular magazine, combining the Mk II gas system with a New Haven, Connecticut-marked barrel and an aluminum alloy receiver. The walnut stock with cut checkering and a Winchester-branded ventilated pad rounds out a well-specified Deer-Slug variant.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Specific Condition Notes: There are markings and areas of surface rust from previous handling and use. The bore is bright and clean. See the photos for a closer look at these areas.
What’s Included
- Winchester Model 1400 Mk II Deer-Slug 12 gauge semi-automatic shotgun
The Deer-Slug configuration centers on a 22.5-inch smoothbore barrel marked DEER-SLUG, set up with a fixed cylinder bore and open rifle sights. It is chambered for 2 3/4" shells, making it a straightforward, slug-focused setup with an unthreaded muzzle and a clean sight picture via a ramp front post and adjustable rear leaf.
Powered by Winchester’s Mk II gas-operated action, this Model 1400 uses a tubular magazine with a 2+1 capacity. Controls include a cross-bolt safety and a bolt-release button positioned at the front of the trigger guard for quick, intuitive operation.
Construction combines a steel barrel with an aluminum alloy receiver in a blued/black finish. The walnut stock features a pistol grip, beavertail forend, diamond-pattern cut checkering, and a Winchester-branded ventilated rubber recoil pad with a white-line spacer. Length of pull measures 14.0 inches.
Barrel markings include MADE IN NEW HAVEN, CONN. U.S.A., aligning with its 1971–72 production window. This Mk II carries an N-prefix serialization associated with post-1968 GCA numbering. Overall, it is a United States-made, 1970s-era Deer-Slug variant with the key features buyers look for: 2 3/4" chamber, cylinder bore, and rifle sights.