The Modern Assault Gun

The assault gun was essentially designed as a direct-support weapon mounted on a tank or other vehicle chassis. The gun was not deployed as self-propelled artillery, but in a direct-fire role supporting infantry forces. Designed during World War II as a cost-effective alternative to tanks and as additional infantry fire support in the great expanses of the eastern front, assault gun battalions were also employed as tank destroyers in both armored and infantry divisions. After the war, assault guns found a home in airborne units, which lacked firepower and whose light infantry roles were limited without effective antitank weapons. Lightweight and proven effective in combat, the assault gun was an excellent weapon; however, missile technology began to supersede guns, especially in antitank roles. The assault gun/tank destroyer was replaced by antitank guided missile (ATGM)-carrying vehicles and armored personnel carriers (APCs), as well as infantry fighting vehicles (IFV) mounting direct-fire weapons. The assault gun, used in infantry support and antitank roles, has two major advantages, cost and flexibility, over modern APCs and IFVs, which may warrant its return to combat service. The assault gun is the perfect infantry support weapon; it is capable of being used as direct-fire, antitank, and antiaircraft weapons, depending on the gun system mounted. Its use in armored formations could be a valuable economy-of-force asset, freeing tanks for rapid offensive action, as opposed to costly assaults. The assault gun’s low silhouette offers protection from enemy fire and its battlefield mobility offers an effective gun platform. During the 1982 operation into Lebanon, Israeli forces came under attack from Syrian SA-342 Gazelle helicopters. Using self-propelled 20mm M-163 Vulcan guns, Israeli forces repelled Gazelle attacks and raked Syrian antitank hunter teams with fire. The multiuse and effectiveness of vehicle-mounted gun systems as infantry support weapons proved to be invaluable. In today’s operating environment, U.S. forces fighting on the frontlines can employ assault guns against enemy infantry, fortified houses, and bunkers, as well as technical weapons mounted on civilian vehicles. This would give infantry commanders an immediate source of fire support without calling for airstrikes that produce collateral damage. Medium- and large-caliber assault guns are capable of firing high-explosive (HE); armor-piercing, high-explosive antitank (HEAT); armor-piercing fin-stabilized discarding sabot (APFSDS); and fragmentation (FRAG) rounds, which are very effective by First Lieutenant Joe Morsello May-June 2009 — 37 against enemy infantry, vehicles, armor, and aircraft when used with multifunction fuzing (point detonating, proximity, and all-way acting). Modern-day HEAT and APFSDS ammunition presents an opportunity for the assault gun to be used once again as a tank destroyer. Tanks destroyers, armed solely with ATGMs, are very effective against armored formations and could be employed against other hardened targets; however, blasting away against pillboxes, bunkers, and light-skinned vehicles with expensive ATGMs is not cost effective. Using ATGMs against enemy infantry would require dual-use missiles, incorporating a FRAG round sleeve or other HE feature, further increasing cost. Additionally, the rate of fire for missile-armed tank destroyers is considerably lower than gun-armed systems. While missile systems can be effective against multiple targets, the assault gun offers simplicity and improved reliability, cost, rate of fire, and ammunition storage options. Lessons from World War II and multiple Israeli-Arab conflicts demonstrate the need for various ammunition types during modern engagements. During the Battle of Stalingrad, German tanks required HE shells for buildings and infantry because AP shells would merely blast a hole through the structure; on the other hand, HE shells were useless against Soviet T-34 tanks. Israeli armored forces also experienced this during fighting in Lebanon against Hezbollah and Syrian forces. They had to employ HE or FRAG rounds against enemy infantry hiding in buildings or in the open; their usual supply of AP shells would blast through multiple structures, leaving little more than 2-foot diameter holes. Luckily, tanks are gun armed and can carry various types of ammunition, but are expensive to produce and maintain, and difficult to transport. They are also designed to engage enemy forces in mobile warfare, exploiting breakthroughs in enemy defensive positions through rapid maneuver. Employing tanks for assaults on fortified positions and urban engagements is not the best use of their abilities, nor is it good economy of force. Fighting in cities during World War II and in Chechnya during 1994, tank guns could not elevate or depress enough to engage enemy forces on rooftops or in basements. Russian troops used antiaircraft guns to “reach the Chechen hunter-killer teams lurking above or below a tank’s main gun elevation and depression limits.”1 Soviet and Israeli forces often resorted to antiaircraft guns when engaging enemy infantry in mountainous terrain in Afghanistan, Chechnya, and Lebanon. While assault guns are not meant to replace tanks (the tank undeniably has its place in the combined arms team), they are a flexible, cost-effective tool in maintaining America’s ability to wage higher intensity conflicts while contributing to the battle against Islamic radicalism. Modern assault guns can mount any gun or howitzer currently fielded, regardless “The assault gun was essentially designed as a direct-support weapon mounted on a tank or other vehicle chassis. The gun was not deployed as self-propelled artillery, but in a direct-fire role supporting infantry forces. Designed during World War II as a cost-effective alternative to tanks and as additional infantry fire support in the great expanses of the eastern front, assault gun battalions were also employed as tank destroyers in both armored and infantry divisions.” 38 — May-June 2009 of its original purpose, to include the autocannon and Gatling gun. The autocannon is any single-barrel weapon, 20mm or larger in diameter, capable of automated firing and loading much like the cannon mounted on the M2 IFV. Instead of recoil actuation, chain guns use an external power source and chain-fed system to cycle the weapon, which is a feature that has been added to various modern guns. Typically mounted on aircraft, the Gatling gun uses multiple rotating barrels also driven by an external power source and chain-fed system. Miniguns are Gatling guns, which fire standard rifle calibers such as 5.56mm or 7.62mm rounds. Gatling guns are very reliable when using an external power source for weapon functioning, and their rates of fire are inversely related to the size of round they fire. Miniguns have a very high rate of fire, but consequently fire small-caliber ammunition. Either way, the auto-Gatling gun has the highest rate of fire available on any gun weapons system. Although this would not preclude using single-barreled guns as assault guns, the Gatling is more flexible. Low-caliber guns are not practical for use in an assault gun system; they are not very effective against hardened structures and armored vehicles. Small-caliber weapons mounted on vehicles are characteristic of a gun truck or armored car system, as opposed to an assault gun. Large-caliber weapons of 105mm and higher are more effective against tanks, armored vehicles, and hard targets, but do not offer target engagement flexibility against infantry and aircraft of a more rapid firing gun. Medium-caliber weapons, such as the 20mm and 30mm, offer the best balance between destructive power, variety of targets that can be engaged, rate of fire, and ammunition variety and capacity. The auto-Gatling gun is capable of very high rates of fire and reliability; using the 30mm caliber would give the greatest ammunition variety, as currently it’s the smallest caliber to fire APFSDS rounds and offer sufficient size for hard target destruction using HE/FRAG. Modern assault guns can be mounted on either a wheeled or tracked chassis and have traditionally been turretless. The lack of a turret, however, severely limits the gun’s ability to engage air targets and ground targets when on confined roads or in urban areas. The modern assault gun should have a 360-degree capable turret with a gun elevation range of -45 degrees to +90 degrees to engage the widest variety of targets in most battlefield situations. Small design considerations, such as gun elevation and depression, are critical to combat effectiveness. A tracked version would be more mobile over rough terrain, better on mud, snow, and sand, and more maneuverable. A wheeled version would require much less maintenance and be faster and kinder than tracks on paved roads, something the civilian population would appreciate. Because a modern assault gun employed with infantry would have to be mobile over all terrain types, especially debris-strewn battlefields, tracks would be the better choice. Developing multiple variants would certainly increase the assault gun’s versatility and expand its capabilities. For example, one option is to mount a large-caliber gun on a tracked chassis with no turret for use in conventional airborne units or on systems that mount other gun calibers, such as 37mm through 100mm, not considered, but available worldwide. Wheeled variants may also have a place; however, assault gun development is driven by tactical experiments and efficacy testing. There are many possibilities in the development of assault guns; however, any development should produce simple, robust, easy-to-use systems borne of tactical necessity, rather than a desire for new gadgets and hardware. Assault guns are cheaper to produce, maintain, and transport than any other vehicle in the Army’s inventory that rivals its capabilities. More cost effective as an infantry support weapon and capable of employing more varied and cheaper ammunition, the assault gun would be a valuable addition to the combined arms team. Organized as four-vehicle platoons, or two- to three-vehicle sections, assigned to infantry or cavalry platoons, or armor, infantry, or cavalry companies/troops, the assault gun is a more flexible, transportable, and cost-efficient weapon on both the conventional and unconventional battlefield. Notes 1Olga Oliker, Russia’s Chechen Wars 1994-2000: Lessons from Urban Combat, RAND Corporation, 25 November 2001. Lieutenant Joseph P. Morsello is currently serving as commander, 430th Ordnance Company (EOD), North Carolina National Guard, Greenville, NC. He received a B.B.A. from Pace University and an M.A. from North Carolina State University. His military education includes Officer Candidate School, Engineer Officer Basic Course, Scout Leaders Course, and Naval School Ordnance Disposal. He has served in various command and staff positions, including observer controller trainer, 189th Infantry Brigade, 1st Army East, Fort Bragg, NC; and engineer equipment platoon leader, supporting the 1st Battalion, 187th Regiment, 101st Air Assault Division and 3d Armored Cavalry Regiment in Iraq. “During the Battle of Stalingrad, German tanks required HE shells for buildings and infantry because AP shells would merely blast a hole through the structure; on the other hand, HE shells were useless against Soviet T-34 tanks. Israeli armored forces also experienced this during fighting in Lebanon against Hezbollah and Syrian forces. They had to employ HE or FRAG rounds against enemy infantry hiding in buildings or in the open; their usual supply of AP shells would blast through multiple structures, leaving little more than 2-foot diameter holes.” May-June 2009 — 39