M29 DAVY CROCKETT WEAPON SYSTEM M64 Recoilless Gun, Part of the M29 Davy Crockett A recoilless gun or rifle is a lightweight weapon that fires a heavier projectile that would be impractical to fire from a recoiling weapon M64 Recoilless Gun on bracket mount Loading 279mm projectile of comparable size. Technically, only devices that use a rifled barrel are recoilless rifles. Smoothbore variants are recoilless guns. M29 Davy Crockett The M29 Davy Crockett is an open-breech, re- coilless, smooth bore, single shot, low-angle fire, Loading propellant charge muzzle-loaded weapon with a 155mm barrel. The M29 Davy Crockett weapon system utilizes projectile, atomic, supercaliber, 279mm, M388. Atomic projectile M388 is a 51 pound, fin-stabi- lized, low-drag projectile which uses a W54-2 Loaded M29 Davy Crockett. The M388 279mm nuclear warhead. atomic projectile is attached to the M2 Loading M2 launching piston/spigot cylinder launching piston/spigot cylinder. Within the M388 projectile is the W54-2 nuclear warhead. Unloaded M29 Davy Crockett {includes the M64 recoilless gun on a bracket mount, plus (1) the gun barrel seated M2 launching piston/spigot cylinder and (2) either of two fixed propellant charges/cartridges, M76 (or M94) "Zone I" or M77 "Zone II", seated in the M64's chamber}. The principal US means of delivering nuclear weapons in the late 1940s and throughout the 1950s was with heavy bombers dropping bombs each large enough to devastate an entire city. The accompanying US nuclear deterrent theory was equally straightforward: if the Soviet Union attacked in Europe, massive retalia- tion would destroy all the invader's industrial centers and military bases. In the late 1940s the Soviet armed forces deployed large numbers of divi- sions with plenty of armor, all support- Davey Crockett M388 Nuclear Recoilless Launcher in a modern-day museum. ed by a considerable air force. NATO was outnumbered on the ground, and the subsequent Soviet development The M29 Davy Crockett of its own nuclear weapons canceled American strategic supremacy in & the Era of Battlefield Atomic Weapons that field. In the 1950s, therefore, the US Army decided “tactical” nuclear A Davy Crockett fully deployed. By Timothy J. Kutta weapons would have to be used to defeat the Soviets in the field, in detail, battlefield conditions. That new Each battlegroup (BG) had about he United States committed in the event of war, but by itself it had determined the only way to stop if they invaded NATO territory. organizational scheme was known as 1,500 personnel, and the theory was itself to defending Western added no new divisions to the order of a Soviet invasion of Western Europe They were said to be “tactical” “Pentomic,” due to the fact each of each division’s BG would disperse away T Europe from Soviet attack battle. It wasn’t until the Korean War was via the use of nuclear weapons. in that they would be used against the reorganized infantry and airborne from each other in the event of enemy when, on 4 April 1949, it formed the the US actually expanded its ground Even after the Korean War expansion, advancing enemy forces as opposed divisions contained five “maneuver nuclear attack but re-concentrate North Atlantic Treaty Organization force. Prior to that, Joint War Plan that policy remained officially in to his homeland cities. The army battlegroups.” They replaced the when it was time to counterattack. (NATO). That consolidated US, JSPC-496.1, codenamed “Broiler,” place for much of the Cold War. therefore also began to reorganize former three-regiment structure. Each BG could be reinforced with European and Canadian commands which was issued on 8 November 1947, its divisions to fight under nuclear artillery, reconnaissance, armor and 36 MODERN WAR 15 | JAN–FEB 2015 MODERN WAR 15 | JAN–FEB 2015 37 other attachments, drawn from the destroyed. To give units more depth, had a bore diameter of just over three rod. When the charge was ignited, division or higher echelons as needed therefore, the army had to come up inches and, again, that was too small. it fi red the projectile out to a range on a mission-by-mission basis. That with a tactical nuclear weapon that The weapons experts then of 1.5 miles. Tests on the gun were larger number of maneuver units per was small, light and highly mobile. turned to the trench mortar designs successful, and the army accepted it division (fi ve BG as opposed to three The fi rst challenge was producing of World War I. The resultant new as the “M28 Davy Crockett Weapons regiments) was supposed to provide a small nuclear shell. After much weapon's basic design called for it System.” It was named after the for quicker reaction countering work and many designs, an explosive to fi re a large rod onto which was legendary American frontiersmen who enemy thrusts and exploiting fl eeting nuclear core was developed that fi tted an 82mm mortar round. One was then a cultural icon because of a opportunities. In the event of a was only 10.75 inches in diameter end of the rod was dropped into the popular movie and television series. nuclear strike, not all the dispersed BG and 15.7 inches in length, weighing mortar barrel. The other end, which The M28 system consisted of would be destroyed and the surviving 23 lbs. That warhead would yield extended past the barrel, had the a gun, tripod and projectile with a units would continue operations. a 10 to 20 ton nuclear explosion, round attached. Because only the total weight of about 170 lbs. It was The army next decided to integrate and the shell casing developed for rod had to fi t inside the mortar, the designed to be transported by jeep or artillery units capable of fi ring nuclear it was 31 inches long and 11 inches round could be of a larger size. other small vehicle, though it was also shells into the new divisions. A new (280mm) in diameter. It was said to Using that as a foundation, the man-portable for short distances. 280mm cannon was designed and des- look like a “watermelon with fi ns.” army designed a 120mm recoilless The M388 round was designed to ignated the M-65. It could fi re a Mark 9 The army originally intended to smoothbore gun that could be loaded detonate 20 feet above the ground. The nuclear shell to a maximum range of 19 use a bazooka to deliver the warhead; with either one of two powder charges. resultant explosion would instantly miles; however, the “Atomic Cannon,” however, that weapon was too small to A long 120mm rod was loaded into kill anyone within 150 yards of the as it was known, was also a vulnerable properly fi t the round, and it couldn’t the barrel with the end extended detonation point and seriously wound target. Further, there were only 20 of provide suffi cient range even if it did. slightly past the muzzle. An 11 inch those out to about 700 yards. That the big guns in the entire US arsenal, The next larger weapon was the recoil- diameter M388 nuclear projectile would give any small US ground unit and they could only move (slowly) with less rifl e. The standard 75mm only was then attached to the end of the considerable fi repower, but it also the aid of specially built tractors. The meant the fi ring team would be dan- Soviets considered the Mark 9s prime gerously close to its own blast zone. targets, and planned to take them out US weapons experts therefore in the fi rst strike of any war. Even a decided to increase the range by 17 July 1962. Little Feller well concealed gun might only get off I test of the M29 at the developing a 155mm recoilless a shot or two before it was located and Nevada Test Site was version. That increase allowed for A view of the jeep-mounted version the last atmospheric nuclear detonation by the United States. The M29's 50-pound M54 warhead packed an explosive punch equal to 10 to 20 tons of TNT. Shown here mounted on an M116 armored personnel carrier, the M29 was meant to be fi red from mountings on jeeps or APCs, or from a dismounted tripod. The larger vehicle-mounted version The powerful but slow-to-move atomic cannon. 38 MODERN WAR 15 | JAN–FEB 2015 This three-man crew seems skeptical of the whole idea. The warhead followed the same Of course, the Davy Crockett ended A cover shot of the FM23-30 Davy trajectory as the spotting gun round. up never being employed in combat. Crockett operator's manual. Once the range was determined, By the early 1970s the balance the crew loaded a round and set the of power was again shifting. NATO division-brigade-battalion organiza- yield, which could be 10 or 20 tons of introduced a new generation of tion. With that reorganization the Davy explosive power. That was small for a improved tanks, such as the US M-60, Crockett was withdrawn from Europe nuclear weapon, but powerful when the German Leopard and the British and then from the entire US Army. viewed from the small-unit level. While Chieftain, which could hold their own By 1971 they had all been retired. tests demonstrated the Davy Crockett against large Soviet armored forma- The effectiveness of the system, wasn’t especially accurate, its designers tions. Other non-nuclear weapons, as well as the practicability of the didn’t consider that to be a fl aw given such as helicopter gunships and wire- decision to place nuclear weapons in each warhead’s area of destruction.