This was the first and only nuclear shell to be fired from a cannon. (The Little Feller 1 test shot of a W54 used a Davy Crockett weapon system, which was a recoilless smooth-bore gun firing the warhead mounted on the end of a spigot inserted in the barrel of the weapon.) After the successful test, at least 20 cannons were manufactured at Watervliet and Watertown Arsenals, at a cost of $800,000 each. They were deployed overseas to Europe and Korea, frequently shifted around to avoid being detected and targeted by opposing forces. Due to the size of the apparatus, their limited range, the development of nuclear shells compatible with existing artillery pieces (the W48 for the 155 mm and the W33 for the 203 mm), and the development of rocket- and missile-based nuclear artillery (such as the Little John and Honest John tactical nuclear missiles), the M65 was effectively obsolete soon after it was deployed. However, it remained a prestige weapon and was not retired until 1963. Of the twenty M65s produced, at least seven survive on display. Most no longer have their "prime movers". The Virginia War Museum in Newport News, Virginia has been erroneously identified as possessing a 240mm prototype of the M65. The weapon at the Museum is actually a conventional 240mm T1 Gun, one of two produced as part of a separate design program which was abandoned in favor of the T131 280mm Atomic Cannon program. Both the T1 and T131/M65 share T72 carriages.