Infantry Anti tank- Armbrust, Matador

Armbrust (German: Crossbow) is a lightweight unguided anti-tank weapon designed and developed by Messerschmitt-Bölkow-Blohm of Germany, who later sold its manufacturing rights to Singapore. The Armbrust equips the Singapore infantry section with basic anti-tank capability.

Comparing the ARMBRUST (top) and MATADOR (bottom)

An Armbrust 67 mm projectile (via Iraq OIG)
The Armbrust is a recoilless weapon, and its design is one of the few weapons of its kind that may safely be fired in an enclosed space. The propellant charge is placed between two pistons with the projectile in front of one and a mass of shredded plastic in the rear. Unlike most recoilless weapons it is a true countershot weapon, the mass of the projectile is equal to the mass of the counterweight and they are ejected from the barrel at the same initial velocity. When the weapon is fired the propellant expands pushing the two pistons out. The projectile is forced out the front and the plastic out the back. The plastic disperses upon leaving the back of the barrel, and is quickly stopped by air resistance. The pistons jam at either end of the barrel locking the hot gases inside.
Its warhead can penetrate up to 300 mm of armoured steel.
Armbrusts are gradually being replaced by the Singapore-German-Israeli co-developed MATADOR, starting 2004.

MATADOR

MATADOR (Man-portable Anti-Tank, Anti-DOoR) is a 90 mm man-portable, disposable anti-armor weapon system developed by Singapore. It is an updated version of the German Armbrust design, and operates on the same principles. The development of this weapon began in 2000 and the MATADOR will eventually replace the German-Singaporean Armbrust Light Anti-tank Weapon which has been in service since the 1980s.[1]
The MATADOR was developed jointly by the Singapore Armed Forces (SAF) and the Defence Science & Technology Agency (DSTA), in collaboration with Dynamit Nobel Defence (DND).[1]