(United States)

As the Iowa class battleships and WWII-era Baltimore and Cleveland class cruisers were retired in the early 1970s, the US Marine Corps faced the realization that the largest amphibious fire support gun existing was 5”, itself available in dwindling numbers. During the Vietnam War, 5” shells were often unable to penetrate coast defense bunkers, and moreover, by 1970 newer Soviet army artillery guns could out-range it.

As future construction centered on carrier escorts, the Major-Caliber Lightweight Gun (MCLWG) programme was launched to provide a heavy, accurate gun that could fit aboard a destroyer or large frigate. Initially a 6.9” caliber gun was envisioned, in the end a 8” weapon was found to be more suitable. The Mk71 was the last US navy gun to use separate-charge ammunition.

The only ship to actually receive the Mk71 was USS Hull (DD-945), which carried it from 1975 to 1979. It was extremely accurate in both the ship-to-ship and shore bombardment tests, and was liked by it’s crew. However it fell victim to Carter-administration budget cuts and was eliminated in the 1978 budget. The Mk71 that was carried by Hull is still in storage at Dahlgren, VA.

Planned installations: Spruance class DD (forward mount only), Ticonderoga class CG (forward mount only, in half the ships of this class), CSGN class (a cancelled “strike cruiser” project), USS Long Beach (CGN-9) (was planned to retrofit).