The Sherman Firefly was based on the British Sherman V , which was the M4A4 Sherman variant of the American Sherman family. More broadly, Firefly conversions were also made on some M4 and M4 Composite Shermans, but the best-known version was the Sherman Vc, or M4A4-based Firefly.

Quick scoop

  • Main base tank: M4A4 Sherman / Sherman V.
  • Other Firefly bases: M4 Sherman and M4 Composite Sherman.
  • What changed: the British replaced the original gun with the 17-pounder anti-tank gun.

In forum-style shorthand: the Firefly was basically a Sherman chassis with a much bigger British gun bolted on.