Missiles grab the glory, but deck guns win close fights. That simple reality explains why the U.S. Navy just pushed another $38.2 million toward BAE Systems to rebuild and overhaul two Mk 45 Mod 4 naval guns.
Naval Sea Systems Command handed the cost-plus-incentive-fee modification to BAE Systems to keep the fleet's surface combatants battle-ready. Money matters in defense procurement, and this particular funding draws from fiscal 2024 shipbuilding allocations that stay active past standard budget limits. Louisville, Kentucky is where the heavy lifting happens, with BAE Systems facilities scheduled to finish the overhaul work by March 2030.
If you think a five-inch gun is outdated tech in an era of hypersonic missiles and drone swarms, you aren't paying attention to recent combat logs. When Red Sea patrols face constant incoming threats from Houthi positions, firing a multi-million-dollar interceptor missile at a cheap drone burns through stockpiles fast. Gun systems offer a high-volume, cost-effective counter. That's why keeping these mechanical workhorses in peak condition is non-negotiable.
What Makes the Mk 45 Mod 4 Worth Saving
The Mk 45 is a 127 mm, 62-caliber weapon system. BAE Systems builds the lightest, most compact, and most widely deployed five-inch naval gun on the planet. Over 260 units protect ships across the U.S. Navy and ten international fleets, including Australia, Japan, South Korea, and Denmark.
Cruisers and destroyers rely on it. Walk the decks of an Arleigh Burke-class destroyer or a Ticonderoga-class cruiser, and you'll find the Mk 45 sitting front and center. It handles everything from shore bombardment during amphibious operations to surface defense and limited air engagement.
The Mod 4 configuration changes the math completely compared to older variants. BAE Systems engineered a structurally reinforced mount that increases firing energy by roughly 50 percent. Rounds leave the barrel faster and travel farther downrange. Pair that enhanced mount with a fully digital control system featuring touch-screen interfaces and a lower-maintenance, reduced-signature gun shield, and you get a lethal upgrade.
When you load the Navy's five-inch Cargo projectile alongside an improved propelling charge, the Mod 4 gun can strike targets over 20 nautical miles away. That's roughly 37 kilometers of reach from a traditional deck gun.
The Logistics Behind the Refurbishments
Overhauling naval artillery isn't like swapping out a car engine. It requires specialized manufacturing capabilities, strict quality control, and deep technical expertise that only original equipment manufacturers possess. BAE Systems has secured a steady stream of these overhaul contracts lately. Back in January 2025, the company picked up a $70 million contract that built on a prior $47 million order.
Executives at BAE Systems have pointed out the obvious connection between ongoing maritime conflicts and these service-life extension contracts. High-tempo operations in the Middle East wear out barrels, stress mounts, and tax digital fire-control systems. Saltwater corrosion, constant vibration, and thousands of high-pressure rounds take a heavy toll on mechanical components.
Rebuilding these guns instead of buying entirely new systems saves taxpayers money while keeping lead times manageable. A complete teardown, overhaul, and recertification process restores a gun to zero-time, zero-mile condition. It gives a warship another few decades of operational capability without waiting for a brand-new hull to slide down the shipyard ways.
What Happens Next for Surface Warfare
Surface warfare is shifting back toward high-intensity conflict. Navies are realizing that relying exclusively on exquisite, high-end munitions leaves them vulnerable to massed attacks. You need a deep magazine and diverse options.
The upcoming years will test whether defense contractors can keep pace with maintenance schedules. With work on these two Mk 45 guns stretching out to 2030, the demand for heavy mechanical refits remains high across naval shipyards. Expect more contract modifications as the Navy continues pushing its existing surface fleet to the limit.
