T72 Gun Motor Carriage
The T72 was developed as an interim design to address problems of an unbalanced turret in the M10 tank destroyer. It used an M10A1 hull with a T23 medium tank turret with the roof removed and the sides thinned. The M10's 3" gun was replaced with a 76mm M1 gun and a counterbalance was added to the rear of the turret.
Ultimately the T72 Gun Motor Carriage was dropped in favour of the M18 Hellcat and M36 Jackson so the T72 never entered service.