APCBC The armour - piercing capped ballistic cap ( APCBC ) is a type of armor - piercing shell introduced in the 1930s . Development . The APCBC munition type was an evolutionary development of the early war armour - piercing capped ( APC ) shell , itself an evolution of the more basic AP ( armor piercing or solid shot ) and APHE ( armor piercing high explosive ) shell types . With respect to armored land warfare , the primary intended function of both AP and APHE shell types was to penetrate an enemy armored vehicle and incapacitate the vehicle and crew by internal explosion ( in the case of APHE ) or fragmentation / ricochet ( in the case of AP rounds ) . As the war lengthened , target armor became progressively thicker ( and sloped ) as new tank designs emerged , and early war AP and APHE became progressively less effective . The initial response to this thickening in armor had been to increase the muzzle velocity in newly developed anti - tanks guns . However , it was found that steel shot tended to shatter on impact at velocities upward of about 823 m / s ( 2700 feet / second ) . Based on this deficiency , a new form of shell was developed which was designated APC ( armor piercing capped ) . In this form of munition , a cap of softer metal was attached to the tip of an AP ( solid ) round . The purpose of this cap was manifold . The cap transferred energy from the tip of the shell to the sides of the projectile , thereby helping to reduce shattering . In addition , the cap appeared to improve penetration of sloped armor by deforming , spreading and “ sticking ” to the armor on impact and thereby reducing the tendency of the shell to deflect at an angle . However , the cap structure of the APC shell reduced the aerodynamic efficiency of the round with a resultant reduction in accuracy and range ' To address the reduction in accuracy caused by the addition of a cap to an AP round , a second cap or cover was introduced in the design of APCBC munition . This involved fitting a streamlined ballistic cap over the APC , thereby increasing accuracy , reducing in - flight loss of velocity and increasing penetration . Early WWII - era uncapped AP projectiles fired from high - velocity guns were able to penetrate about twice their caliber at close range ( 100 m ) . At longer ranges ( 500 - 1 , 000 m ) , this dropped to 1 . 5 - 1 . 1 calibers due to the poor ballistic shape and higher drag of the smaller - diameter early projectiles . Later in the conflict , APCBC fired at close range ( 100 m ) from large - caliber , high - velocity guns ( 75 – 128 mm ) were able to penetrate a much greater thickness of armor in relation to their caliber ( 2 . 5 times ) and also a greater thickness ( 2 - 1 . 75 times ) at longer ranges ( 1 , 500 - 2 , 000 m ) . Comparative testing of British Ordnance QF 17 pounder APCBC rounds fired into captured German Panther tank s indicated the APCBC munitions were more accurate than late war armour - piercing discarding sabot ( APDS ) shot . APCBC shot was produced for a wide range of anti - tank artillery ranging from 2 pounders to the German 88 mm . This type of munition was also designated as APBC ( Armor Piercing Ballistic Capped ) , in reference to the Soviet version of APCBC . APCBC shot was also used in naval armaments in WWII . After World War II , the trend in armor piercing munitions development centered on sub - caliber projectiles . No tank guns designed since the late 1950s have used full - caliber AP , APC , or APCBC ammunition .