In 1971 Colt unveiled a new modern service pistol, one that the company believed was the natural successor to the venerable Colt M1911/A1. At first glance, the Model 1971 looks very similar to the 1911. However, the new pistol incorporates some major changes.

Developed by the Research and Development Department of Colt Industries’ Military Arms Division, the M1971 is a double-action, single-action semi-automatic pistol. It comes in nine-by-19-millimeter, .38 Super and .45 ACP. The former two calibers allow the use of a double-stack magazine for increased capacity, while the .45 ACP version’s capacity is nine rounds.

The pistol was designed by Robert Roy and a team at Colt between 1968 and 1970. The technical report Colt released with the pistol claims that the nine-millimeter model’s increased magazine capacity compared to the 1911 eliminates the need for troops to carry additional ammunition.

The technical report on the pistol also includes an interesting section about Colt’s Salvo Squeeze Bore concept — a multiple-projectile cartridge system that could, in theory, increase the pistol’s firepower.

The new pistol is shorter than the 1911 and also five ounces lighter. The 1971 also boasts a slide-mounted de-cocker/hammer-block safety similar to that on the Walther P38, replacing the 1911′s manual and grip safeties. Colt uses blued stainless steel alloys in both the frame and slide. The company justified the added expense by noting that corrosion accounted for the majority of M1911A1s deemed unfit for service after time in storage.

Colt’s aim was to introduce a new modern sidearm that could sell internationally and could also compete with Smith & Wesson’s semi-automatic pistols, such as the Model 39 and Model 59. The M1971 also represented an attempt by Colt to anticipated a U.S. military effort to replace the M1911A1.

Colt produced between 30 to 50 M1971 pistols. With no major sales, interest Colt shelved the pistol until the U.S. Department of Defense launched its Joint Service Small Arms Program — an initiative to replace the 1911 — in 1979. Colt resurrected the M1971 with some minor changes, including an ambidextrous safety and a contained removable fire-control mechanism.

The manufacturer dubbed this new pistol, which unlike the M1971 is not blued, the Colt Stainless Steel Pistol — and manufactured approximately 50 of them.

The standard Colt SSP comes chambered for nine-millimeter, as required by the military trial, and does not include the Salvo Squeeze Bore concept. But some .45 ACP examples do exist. The SSP competed against a number of contemporary pistols including the Walther P88, Smith & Wesson 459, Beretta 92, Sig Sauer P226 and Steyr GB and HK P7.

Beretta’s 92 won the first set of trials. But the Army objected and, in 1983, the Defense Department ran another trial. The SSP competed, but the Beretta won out again with the Model 92. The U.S. military adopted the Model 92 in 1985, calling it the M9.

This article by Matthew Moss originally appeared at War is Boring in 2016.

Image: Wikimedia