The Sherman 75mm

[David Dunlop]

Considering all the complaints one reads about regarding this standard Sherman main gun, could a simple fix not have been to extend the length of the original barrel by a factor of 2 or 3? When the Germans did this with the Panther Main Gun, it certainly improved the range and velocity of the shell.

[Geoff Winnington-Ball (RIP)]

Originally Posted by David Dunlop

Considering all the complaints one reads about regarding this standard Sherman main gun, could a simple fix not have been to extend the length of the original barrel by a factor of 2 or 3? When the Germans did this with the Panther Main Gun, it certainly improved the range and velocity of the shell.

Not really in this case. The standard 75mm Sherman gun shell case just didn't hold enough "umph", which is why they went to the 17-pounder (76.2mm), which did. The Americans later went to the to 76mm gun, which of course did as well, albeit perhaps not quite as well, hence the adoption of the 90mm later. The original 75mm was good in 1942 but that was the end of its service life except in extraordinary circumstances.

[John McGillivray]

Sherman tanks were mainly used to provide close support for the Infantry. In this role they fired a much greater number of HE rounds than AP. In Normandy I’ve heard of a 3 to 1 ratio of HE vs. AP. In other fronts there was an even greater imbalance. For example on the 13th of May 1944 in Italy, two Regiments from the 1st Cdn Armoured Brigade fired 1555 HE rounds and only 50 AP rounds.

The Sherman 75 also had a smoke WP round. In Radley-Walkers bio he tells of how they would use smoke to blind German positions. The German tanks would always moved up wind to get open fields of fire, however, the 17 pdr Fireflies would be waiting in ambush positions to kill the panzers as they came out of the smoke.

Stuart Hill who was a troop commander with the Nottinghamshire Sherwood Rangers Yeomanry, wrote in his book “By Tank into Normandy” that the main weapon of the Sherman tank were the machine guns. They were the weapons that were used most often to engage targets. He criticized the Firefly for its lack of a hull MG.

Note that the 17pdr HE Mk 2 that was used with the Firefly tank was smaller and lighter than the 75mm HE and therefore weaker. The 17pdr Mk 1 HE was closer to the 75mm in performance, but because of its length (three inches longer that the Mk 2) it could only be used with the 17pdr A/T guns and not in the Firefly.

[Bob Cohoon]

I think changing the length on the 75mm barrel would have increased muzzle velocity, but this probably increases chamber pressure too, so tests and calculations would have had to be made to see if the breech block, chamber, recoil mechanism, mounting, etc. could stand this. I guess the priority at the time was developing the new 76mm design which was suppose to be the answer to equalizing things. The 76mm with HVAP(hyper velocity armor piercing) ammo,scarce at the time, cold perform about the same as the Panther 75mm.The M18 tank destroyers had this and the Sherman 76mm crews would try and trade for a round or two of this for emergencies, I read that in the book "M4 Sherman".

[John McGillivray]

Increasing the barrel length of the 75mm gun, without changing the ammunition, would only yield a small increase in performance.


75mm M2
Barrel length (length of tube): 84in
Muzzle velocity: 1,860fps
Armour Penetration: 60mm at 500 yards/30deg.

British 75mm Mk V
Length of tube 107.8in
MV: 2,030fps
AP: 68mm @500yards/30deg

75mm M3
Length of tube 110.625in
MV: 2,300fps
AP: 70mm @500yds/30deg

6pdr Mk III
Length of tube: 96.2in
MV: 2,800fps
AP: 81mm

6pdr Mk V
Length of tube: 112.2in
MV: 2,965fps
AP: 83mm @500yards/30deg