We’ve talked before about the Bradley’s main gun, the M242 Bushmaster 25mm cannon. The M242 is also mounted on the Marine Corps Light Armored Vehicle family of wheeled APCs. Additionally, the Navy uses the Bushmaster.
Several years ago, the Navy realized that their large combatant ships were very well equipped to sink the ships of just about any other Navy. What they weren’t equipped to deal with were small boats swarming around them in confined waters such as the Persian Gulf. Even before the suicide small boat attack on the USS Cole in December 2000, the Navy realized the dangers small boats could pose to large ships. But 5″ guns and Harpoon missiles aren’t the best weapons to defeat that threat. What you need is a smaller, faster firing gun. The first weapons mounted were old standbys, such as the M-60 machine gun, and that old reliable, the M2 .50 cal machine gun. But machine guns have a fairly short range, limited penetration against even fiberglass hulled boats, and aren’t terribly accurate when fired from a moving platform. Something bigger was needed. And in stepped the Bushmaster. The Navy quickly developed a simple mount for the 25mm gun that could be bolted to the deck of a ship. The Mk38 mount could be operated by one man, was fairly inexpensive (compared to shooting a Harpoon at a Boston Whaler), and was quick to produce. And since they could be bolted to the deck, they could also be unbolted, and shifted from ship to ship. That meant the Navy only needed to buy enough to equip those ships that were in harm’s way. As ships entered the Persian Gulf, they would swap out the guns with those that were leaving. That meant the Navy didn’t have to buy a whole lot of guns.
As you watch the video, you’ll notice that even on a large ship, there’s quite a bit of motion, and that mak es aiming the weapon difficult. And even with a gun as great as the 25mm, if you don’t hit the target, you’re not doing much good. Something better was needed. The gun itself was fine, but the mount left a lot to be desired.
Enter the Mk 38 Mod 2 mount. It is still a bolt-on mount, but it is quite a bit more sophisticated. Instead of being manually aimed, it is a remotely operated system, on a stabilized mount, with an electro-optical sighting system for day and night use. By stabilizing the mount (much like the gun stabilization on a Bradley), the pitch, heave and roll of the ship no longer effects the aim. This increases the effective range of the weapon greatly. And of course, now with the E/O sight added, it can be used at night. As an added benefit, the system is now run from the ships Combat Information Center. The display from the sight can be used for surveillance, not just aiming the weapon.
The Mk 38 Mod 2 will be a self-protection weapon aboard US ships such as guided missile cruisers and destroyers operating in confined waters such as the Persian Gulf.
The M242’s bigger brother, the 30mm Mk46 will serve as secondary armament on board amphibious ships such as the LPD-17 class and the Littoral Combat Ships (LCS).