After 15 years of development, the U.S. Army’s new XM-AMP (Advanced Multi-Purpose) 120mm tank round was considered stable enough in 2020 to be test fired by troops. Covid19 delayed that for a year and two tank crews finally were able to fire the AMP in September 2021. That was considered a success but more development is required before the AMP is certified safe and reliable enough for regular use.
By 2013 the AMP had been tested and demonstrated that it worked, but it was still not rugged and reliable enough. The army admitted that at least five years of development and testing was needed to make it suitable for service. That “several years” is turning into a decade. Part of the delay was adding some new features and modifying the shell design to prevent failures by one of the several different features the tank gunner can select before firing.
For decades the army has been developing multi-purpose shells, but by the late 1990s that meant two functions. AMP was a lot more ambitious as it was designed to replace four different shells; the current multipurpose (bunkers and light armored vehicles) M830A1 (and its improved version M908), the HEAT (shaped charge anti-tank) shell, and the M1028 (“shotgun” shell) rounds. The AMP was designed to have instant, delayed, and airburst detonation. This allows the gunner to quickly select the type of detonation that is best able to take out different targets (personnel, light armor, and structures). AMP can penetrate reinforced concrete walls and kill or wound troops more than 500 meters away.
Currently there are similar shells like the DM11 (used by the German Army, Hungary, and U.S. Marine Corps) that are effective against personnel and structures. The DM11 was used in Iraq and Afghanistan. The DM11 is one of several new multi-purpose tank gun shells, and these shells have proved very useful. These new shell designs are better at killing infantry, and destroying bunkers and buildings than tanks and began to appear in the 1990s.
There were still a lot of older shells that are somewhat multipurpose. Over 19,000 American M830A1 multipurpose 120mm tank gun rounds were modified to become M908 shells, which are more lethal against bunkers, buildings, and unarmored vehicles. In addition, there is the M1028, a 120mm shotgun shell containing 1,100 10mm tungsten balls, which can kill or wound at up to 700 meters. This shell and the M908 are what American M-1 tanks used most frequently in Iraq.
Israel pioneered the use of multi-purpose tank gun ammunition and has been using their versions heavily in Palestinian areas for over a decade. These multipurpose shells make tanks much more useful in urban fighting. Hostile gunmen often take cover in buildings or trees and crops. The multipurpose shells can knock down buildings, and the M1028 can clear out anyone sniping at you from lighter structures or vegetation. The AMP will be able to detonate behind obstacles as well, killing troops who were usually safe from tank gun fire in the past. AMP is also effective against most armored vehicles, but will only damage most tanks. Tank crews will still have to carry AP (armor piercing) shells. Experience since World War II (1939-45) has shown that most tank fire is not at other tanks but at structures and troops. The biggest danger to tanks is still anti-tank mines, large roadside bombs and infantry armed with a variety of ATGMs (anti-tank guided missiles) and advanced RPG (shoulder fired rockets) with warheads that can do serious damage to a tank.