err, no...
Items called "shaped-charge armour piercing warheads" do not exist. Shaped charges are armour-_defeating_ warheads. AP projectiles do their thing by being big, and heavy, and moving fast and punching through armour by sheer force. Examples range from 30-mm depleted uranium bullets, as fired by the A-10's big Gatling gun, to 15" dreadnought main gun rounds, such as may be found at the Imperial War Museum. See <http://en.wikipedia.org/wiki/File:15inchgunsatImperialWarMuseumLondon.jpg> for examples of the guns and rounds for them.
Armour-_defeating_ rounds use chemical, electrical, or nuclear explosions to smash or tear or otherwise penetrate armour. Shaped charges in particular use chemical explosives to convert a metal lining, often copper, into a focused jet of plasma which propagates at hypersonic speeds and does the actual penetrating of the armour. The shaped-charge round itself moves quite slowly, and this tends to keep the recoil down to manageable levels. It also means that quite small weapons can defeat fairly large thicknesses of armour. A weapon which fired a 25-mm AP projectile would not be man-portable, or capable of being fired from the shoulder. See further the 25-mm Bushmaster automatic cannon fitted to, among other things, the American Bradley fighting vehicles. <http://en.wikipedia.org/wiki/M242_Bushmaster> Note how much the thing weighs... Captain America couldn't carry that thing into action.