The U.S. Army is upgrading some of its Stryker 8x8 wheeled armored vehicles with the Mk44 30mm Bushmaster cannon. This is weapon is based on the M242 25mm weapon long used in the M2 IFV (Infantry Fighting Vehicle). The MK44 has also been proposed as an upgrade for the M2. The 30mm cannon is much more important for Strykers, which currently have a 12.7mm machine-gun. The Mk44 is much more effective against light armored vehicles and infantry than the 12.7mm machine-gun.
The Mk44 weighs 157 kg (344 pounds) and fires at 100 or 200 rounds per minute (up to 3 or 4 per second). The Bushmaster has 160 rounds available, before needing a reload. That means the gunner has 25-50 seconds worth of ammo, depending on rate of fire used. Each 30mm high explosive/incendiary round weighs about 714 g (25 ounces, depending on type). The fire control system and night vision sensors enables the 30mm gunners to accurately hit distant targets with high explosive shells. The Mk44 also has airburst shells that are automatically programmed by the fire control system to detonate at a specific range. These would be used against helicopters, giving the Stryker an improved (over the 12.7mm machine-gun) capability. Max range of the 30mm shell is 3,000 meters. While the Mk44 is 34 percent heavier than the M242 and has the same range and rate of fire, the 30mm shell is 50 percent more destructive. The Mk44 uses 70 percent of the same parts as the M242.