| SureFire MGX | |
| Origin: | United States |
| Type: | Squad automatic weapon, Light machine gun |
| Is Ranged: | YES |
| Designer: | Jim Sullivan |
| Manufacturer: | SureFire LLC |
| Cartridge: | 5.56×45mm NATO |
| Caliber: | 5.56mm |
| Action: | Gas-operated, rotating bolt |
| Feed: | 30-round detachable STANAG magazine |
The SureFire MGX is a light machine gun designed by Jim Sullivan, Bob Waterfield, Alan Ostrowski, Paul Latulippe Jr. and Hyunjung Samuel Eyssautier in 2002 and produced in prototype form only by ArmWest, LLC and marketed by SureFire, LLC as a technology demonstrator.
The SureFire MGX is a light machine gun featuring various elements from the many arms Sullivan designed in the past. The MGX is essentially a unified machine gun and rifle concept, similar to that of the Stoner 63 system. It is also noted to feature a very similar bolt components to the AR-15 and the various operations and quick change barrel of the Ultimax 100. The weapon fires from a closed bolt when firing semi-auto and from an open bolt when firing full-auto. The MGX features a stock that can fold both ways and can also be removed.