Function of an APFSDS sabot red: propellant orange: long rod penetrator yellow: propellant gases green: sabot blue: gun barrel
M829A2 cross-section
American 120 mm M829A2 APFSDS shell.
Lead bullet being supported by a wooden cup sabot in a Delvigne gun.
Series of individual 1/1,000,000 second exposures showing shotgun firing shot and expanding cup sabot separation.
Cup sabot function
thumb|Sabot shell with cup sabot for an 1824 Paixhans gun.
Expanding cup sabot function
.30-06 cartridge with expanding cup sabot projectile.
Base sabot function
APDS-projectile with base sabot and "support ring" sabot.
Spindle sabot function
French OFL 120 F1 APFSDS long rod penetrator with "saddle-back" spindle sabot.
Ring sabot function.
Soviet 125 mm BM-15 long rod penetrator projectile with ring sabot.

The M829 is an American armor-piercing, fin-stabilized, discarding sabot (APFSDS) tank round.

- M829

(See for example the development of the M829 series of anti-tank projectiles beginning with the base model M829 in the early 1980s, to the recently fielded M829A4 model, employing ever longer "double-ramp" sabots).

- Sabot (firearms)
Function of an APFSDS sabot red: propellant orange: long rod penetrator yellow: propellant gases green: sabot blue: gun barrel

1 related topic

Alpha

APFSDS at point of separation of sabot

Armour-piercing fin-stabilized discarding sabot

Type of kinetic energy penetrator ammunition used to attack modern vehicle armor.

Type of kinetic energy penetrator ammunition used to attack modern vehicle armor.

APFSDS at point of separation of sabot
Modern 120 mm tank gun shells

Above a certain minimum impact velocity necessary to overcome target material strength parameters significantly, penetrator length is more important than impact velocity; as exemplified by the fact that the base model M829 flies nearly 200 m/s (656 ft/s) faster than the newer model M829A3, but is only about one half the length, wholly inadequate for defeating state-of-the-art armor arrays.

Complicating matters, when foreign deployment of military forces or export sales markets are considered, a sabot designed specifically to launch a DU penetrator cannot simply be used to launch a substitute WHA penetrator, even of exactly the same manufactured geometry.