The M27 was an American medium tank. It was produced but was never sent overseas. It was part of the T20 series of tanks which were all designed to replace the M4 Sherman. The difference between T20, T22 and T23 was the transmission. The M27 was known during the design phase as the T23E3, the T23 tanks had a new electric transmission system. The first T23 prototypes had different armament, the T23E1 had a 75 mm gun with an autoloader and the T23E2 had the same three inch gun as the M10 Wolverine. The T23E3 that became the M27 would have the new M1 76 mm gun.
The M27 tank was first introduced in FHSW in v0.5 as the T23E3, it was renamed to M27 in v0.55.