Conflict Special Study 1

Comparative Ammunition Chart

by TP Schweider

The T-54/55 tanks of thc Arab armies utilize AP (Armor-Piercing) ammunition in their 100mm rifled guns. The velocity, weight, and hardness of the solid steel projectile determine its penetration of the target's armored protection. Simple to manufacture and use, AP rounds rely on sheer force and mass for success and suffer in performance against heavily-armored, well-designed enemy vehicles. A low ballistic coefficient, meaning more aerodynamic drag in flight, limits the speed, range, and accuracy of this projectile, and, not surprisingly, more effective designs have been developed. One of these is the HVAP (Hyper- Velocity, Armor-Piercing) round which is basically a smaller solid shot within a shaped covering (a "sabot"). The catire shell travels to the target but only the smaller inner core penetrates the armor. This round is only marginally more effective than the solid AP round.

The smoothbore (i.e., having no rifling) guns of the T-62 tanks employ a sophisticated round designated as APFSDS (Armor-Piercing, Fin-Stabilized, Discarding Sabot) ammunition. Upon leaving the gun muzzle, the projectile sheds its thin outer shell (the "sabot") and its tail fins guide it more accurately to thc target. Fin-stabilization (as opposed to spin-stabilization) allows a hotter charge and increased length (with less aerodynamic drag) for the projectile, giving it higher velocity and greater penetration power than blunter configurations. Barrel wear is also reduced. The effective range of the APFSDS round is about the same as for the AP ammunition so improved armor penetration (about 20 percent better than previous AP rounds) is the major advance of its complex design.

APDS (Armor-Piercing, Discarding Sabot) rounds are standard for Israeli tanks Rifled guns provide accuracy and high velocity enables the tungsten carbide core to effectively pierce armored plate at ranges beyond a mile. The APDS round has had a tendency to richochet off angled armor, but new versions are fitted with a cap, and once inside the target, it produces satisfactory results with its bulky slug. Fragments from the discarded sabot covering can endanger personnel outside the firing tank, but the long range and relatively flat trajectory of this projectile make it ideal for target destructron on the desert battlefield.

The 105mm guns of the Israeli tanks also use HEAT (High Explosive Anti-Tank) rounds. When the probe of the projectile makes contact, a fuze generates an electric current that explodes the base detonator, igniting the explosive. The resulting heat and pressure is shaped by an internal cone into a narrow, high velocity jet stream that burns through armored plate much like an acetylene torch. Molten metal and fragments from the armor itself then spray inside the tank. HEAT rounds do little damage to solid features and are most decisive when penetrating the fighting compartment. However, the effects are not always devastating because of the limited debris produced, so new charges (such as the metal-sheathed P-charge) have been developed which splinter og large fragments able to ignite everything inflammable they strike.

Israeli Centurion tanks fire the HESH (High Explosive Squash Head) round. When this shell strikes its target, a plastic explosive filler spreads out to form a "blob" and is detonated by a tease fuze. A "dinner plate" size dent is left on the outside, but inside, a shock wave is produced and spalling occurs as chunks of metal fly off with deadly effect. Successful at any angle of impact, HESH can also extensively damage running gear and surface features and is a useful ammunition against field fortifications and "thin-skin" vehicles. A major drawback to HESH, however, is that it must hit bald armor for maximum results. Exterior stowage or protective screens can absorb its shock. The HESH round, like the HEP (High Explosive Plastic) ammunition of the U.S. Army, also has been criticized for its relatively lower velocity and poorer accuracy and so is generally ranked behind the APDS and HEAT rounds for tank engagements. Significantly, the Israelis used HESH ammuninon primarily against targets in defilade, bracketing them with successive rounds, and (usually by the third shot} hiting the thin top armor.

SUMMARY

Each variety of tank round described represents a different approach to the complex problem of tank fighting, a quest which has been going on since World War II. While their theoretical lethality has been stated and tested (although rarely proven in a combat environment as in the Middle East), the tank-killing capability of any type of ammunition is a function of a set of diverse variables, covering generally the firing tank, the target, and the battlefield conditions. Tank shells also have individual characterisacs of physical specifications, performance, and destructibility. These distinctive profiles have not unexpectedly led to many modern tanks stocking different types of ammunition for different missions. Comfort has also been taken in the "rule" that the first round fired usually decides a tank engagment.

However, that round (assuming penetration) must destroy vital equipment, cause an explosion, or eliminate the crew; otherwise, the hit tank may go on fighting as the Israelis (and others) have done on occasion. A hit, despite the sophisticated ammunition currently in use worldwide, does not guarantee termination or even neutralization of a foe. Until an absolutely perfect round is developed, one can expect further refinements andadditions to the plethora of tank ammunition which exists today.

More Arab-Israeli Armor 1973

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