The GForce Arms MKX3 Hammer12 12 Gauge Shotgun (brand part no. GF12HMRB) is a magazine-fed semi-auto from GForce Arms built around an 18.5-inch barrel for a short, fast-handling 12 gauge. It ships with a 5-round magazine and flip-up front and rear sights, giving it a straightforward, tactical-style setup ready for home defense or the range. A multi-choke system lets the gun adapt to different shot patterns, and the semi-automatic action keeps follow-up shots quick and manageable.

Key Specifications

• Chambered in 12 gauge for standard shotshell compatibility.
• Runs an 18.5-inch barrel for a short, maneuverable overall length.
• Feeds from a magazine holding 5+1 rounds.
• Ships with one 5-round magazine included.
• Fitted with a flip-up front sight.
• Paired with a flip-up rear sight.
• Includes a three-piece choke system (Cylinder, Full, Modified) for versatile patterning.
• Cycles on a semi-automatic action for fast, controllable follow-up shots.
• Ships at approximately 12 lbs in its case.

Frequently Asked Questions

How many rounds does the MKX3 Hammer12 hold? 5+1, or six total rounds ready to fire with a full magazine.

Are the sights adjustable? Yes, the flip-up front and rear sights can be folded down or deployed as needed.

Buy the GForce Arms MKX3 Hammer12 12 Gauge Shotgun

For a short, magazine-fed 12 gauge with a straightforward tactical setup, the MKX3 Hammer12 is built to be picked up and run. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, or browse our full lineup of semi-auto shotguns to compare configurations.