Well. . . . . . .The 17pdr wasn't without its troubles. There was never really an effective HE round for the gun and so Fireflies were fielded with 2 - 5 regular Shermans to protect them from enemy troops! (usually hiding in a building with an AT gun or Panzerfaust)

There were quite desperate problems initially with the solid shot that often didn't penetrate where a 2pdr would, but shattered on impact and the accuracy of the sabot ammunition; this was indeed very powerful if only you could hit something with it.

These problems were overcome, but almost too little too late.

Of course the enemy knew well what the Firefly could do and so it was the prime target, I would suspect the Firefly crew knew this too. . . . . . . . . . . Allied command was well aware and had various camo schemes to attempt to disguise the long 17pdr barrel, plus the idea of a short dummy barrel on the turret rear with the real one being less obvious depressed over the engine deck; all very well but the gun is then never pointing anywhere near the desired direction.

Received wisdom suggests the Firefly A57 multi-bank to be the best of the engines of the period; certainly Chrysler seemed to prove this on extended endurance tests where only a change to the exhaust valve material was needed to ice the cake as it were.

However, I would imagine when it does have a minor fault, the very nature of 30 cylinders to isolate and diagnose was a nightmare.

For whatever reason the Americans chose not to operate the A57 but rather to donate it to the British and others.

Hanno and Adrian B are our Sherman men, perhaps they can add some insight and corrections.

R.