The new tank's firepower requirements were met by fitting a British Royal Ordnance L7A1 main gun. This gun was later replaced by the modified L7A2 and finally by Rheinmetall's Rh-105-30 gun. This gun is manufactured in Argentina as the FM K.4 "Modelo" 1L. The Rh-105-30's advantages include low weight, compact size and increased lethality. Unlike the Rh-105-30, the FM K.4 does not have a muzzle brake. The locally built cannon can be elevated to 18 degrees or depressed to -7 degrees on the TAM. The gun's hydraulic recoil mechanism has an extended length of to absorb the recoil force. It is designed to fire the M735A1 armor-piercing fin-stabilized discarding sabot, which can penetrate a maximum of at . It can also fire high-explosive anti-tank rounds, high-explosive squash head and smoke rounds. The tank's secondary armaments include a co-axial FN MAG 60-40 general purpose machine gun and a second FN MAG 60-20 mounted on the TAM's turret roof as an anti-aircraft machine gun. The fire control system includes a with a range of and a FLER-HG ballistic computer to compute the gun's fire solutions—helping the gunner aim and hit the target. The tank commander uses a Zeiss PERI-R/TA panoramic periscope, with a 2x and 8x zoom.