modern battle tank how many armor piercing

To reduce the spin rate when using a rifled barrel, a 'slip obturator', (slip obturation ring), is incorporated that allows the high pressure propellant gasses to seal, yet not transfer the total spin rate of the rifling into the projectile. Nevertheless, in the early development of APFSDS ammunition, existing rifled barrel cannons were used, (and are still in use), such as the M68-105mm cannon mounted on the M60A3 main battle tank. For these reasons, APFSDS projectiles are generally fired from smoothbore guns, a practice that has been taken up for tank guns by China, India, Israel, Italy, Japan, France, Germany, Turkey, Russia, and the United States. The spin from standard rifling decreases the performance of these rounds (rifling diverts some of the linear kinetic energy to rotational kinetic energy, thus decreasing the round's velocity and impact energy), and very high rotation on a fin-stabilized projectile can dramatically increase aerodynamic drag, further reducing impact velocity. Adding fins like the fletching of an arrow to the base gives the round stability. Up to a certain limit, this is effective, but once the projectile's length is more than six or seven times its diameter, rifling becomes less effective. Traditionally, rounds were given stability in flight from the rifling of the gun barrel, which imparts a spin to the round. However, a long, thin rod is aerodynamically unstable it tends to tumble in flight and is less accurate. The logical progression was to make the shot longer and thinner to concentrate the kinetic energy in a smaller area.

Armour-piercing discarding sabot (APDS) was initially the main design of the kinetic energy (KE) penetrator.

Modern battle tank how many armor piercing