U. S. Army Tank Ammunition Tests, 1970

   The following is an extract from USAREUR Pamphlet 525-1, 30 September 1970, published by HQs, US Army Europe & 7th Army.  The pamphlet was titled "Military Operations - Tips for Tankers," and contains instructions on how to defeat enemy armor.  The pamphlet was produced in West Germany during the Cold War, when U.S. M60A1 tanks opposed a vast number of Soviet T-55 and T-62 tanks, across the border in East Germany.  The pamphlet was unclassified.

   The ammunition tests were conducted in the spring of 1970 at the 7th Army Combined Arms School training and gunnery area at Grafenwöhr, West Germany.  The target vehicles were old U.S. M-26 tanks that had been rebuilt, with most components mounted and combat stowed.  Fuel tanks were at least half full of gasoline, but no ammunition was stowed.  U.S. tanks fired the three main types of 105mm main gun ammunition then in use: M392 armor-piercing discarding sabot (APDS), M456 high explosive anti-tank (HEAT), and M393 high explosive plastic (HEP).   The sabot round was a kinetic energy round carrying no explosives; it defeated its target by punching through with a dense penetrator.  HEAT contained a shaped-charge warhead that produced a jet of gas and molten armor that burned through the target.   HEP was not normally used against armor, as it would not generally penetrate, but these tests showed that it had an effective spalling capability.

   Sabot rounds were fired at ranges from 1200 to 3600 meters.  None of the rounds ricocheted, regardless of point of impact or range.   There was little exterior or interior damage around the point of impact, but the interior surface opposite the site of penetration showed splatter from the breakup of the sabot round, and broken armor.  This splatter would have been debilitating to any crewmen.

Sabot penetration hole on the right turret side, 3600 meters

Sabot interior penetration hole, and splatter on the opposite side of the turret, 3600 meters

   HEAT rounds were fired at ranges from 500 to 2600 meters.  HEAT consistently penetrated the front slope and turret of the target.  HEAT caused considerable damage to components both outside and inside the target, due to the explosion from the shaped charge.  The plasma jet burned all the way through both sides of the turret at 2200 meters.

HEAT entrance hole and exterior damage from explosion
on the left side of the turret, 2200 meters

HEAT damage to the inside of the turret (radio mounts),
and exit hole on the right side of the turret, 2200 meters

   HEP was fired at ranges from 500 to 1800 meters.  HEP was called HESH (high explosive squash head) in British service, and was not normally fired at armored targets.  Due to its comparatively slow trajectory and non-penetrating characteristics, HEP was designed to defeat lightly armored vehicles and stationary targets such as bunkers and buildings.  When the HEP round impacted, a delayed fuse allowed the projectile to "squash" and spread the plastic explosive filler on the target before detonation.  Thus, the explosion was spread over a larger area.

   The HEP rounds fired in this test did not penetrate the armor, but they caused massive damage, both inside and out.   The explosion dented the armor on the outside, and ripped away adjacent items such as stowage boxes, sponsons, and track.  When the round impacted on bare armor, a pie-plate size piece of metal was blown off the inside surface, spraying chunks of armor spall across the crew compartment.  Thus, even though the HEP round did not penetrate, it caused lethal damage to the target.

HEP impact crater on the left turret exterior at 1800 meters (note previous HEAT entrance hole,
from the shot above), and spall point on the left turret interior.  This piece of armor was thrown
off the interior wall in chunks of spall, which sprayed across the turret.

   Notes from an ex-tanker  ...  Readers familiar with "Graf" will wonder where the testers found ranges of 3600 meters to fire at.  The longest tank shot I ever saw at Graf (1979-1982) was about 2200 meters (the hard targets on the ridgeline on Range 20).  We were only allowed to fire "service" sabot (the actual wartime round, as opposed to training rounds) in one area, and the maximum range was 1800 meters (due to ricochet danger).

   The HEP tests gave surprising results.   One surprise, in addition to the target damage, was firing HEP at 1800 meters.   The HEP round was quite slow (compared to HEAT and sabot), with a visible trajectory arc.  We rarely fired practice HEP at over 1000 meters, because it was easy to miss, either over or short (these were M60A1 RISE Passive tanks, with old coincidence rangefinders and analog computers).  I will say, though, that one of the prettiest main gun shots I ever saw was with practice HEP.  We were training my driver as a gunner, and he was tracking a moving target at 1200 meters, with training HEP loaded.  He was getting close to the range fan marker on the right, and I had just opened my mouth to command "cease fire," so the round wouldn't be fired outside the safety area, when he pulled the trigger.  That HEP round sailed up into the air and down toward the target, and went through the middle of the turret, just a foot or two before it passed the range fan.  TARGET!

All photos from U.S. Army collections.

URL  --  http://www.waldenarchives.simonides.org/ka/tankammo.htm

   Contact page author Geoff Walden at gwalden1864@earthlink.net

Geoff Walden is a member of the AFV Association (# 2158), and a former Armor Officer in the US Army.

Other pages of interest:

http://www.waldenarchives.simonides.org/ka/kosovoarmor.htm
Armor in Kosovo, Yugoslavia, 1999 - Geoff Walden
Lots of photos of damaged and destroyed Yugoslavian vehicles from the 1999 campaign, and NATO KFOR vehicles during the subsequent occupation.

http://www.waldenarchives.simonides.org/pz/panzercolors.htm
WW II German tank paint and camouflage - Geoff Walden

http://www.waldenarchives.simonides.org/tr/reichruins.htm
"Third Reich in Ruins" - then-and-now photos of many Nazi sites and buildings

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