"M 7 SPG Hull" Topic

Could the hull of the M 7 Priest SPG hold a 90mm AAA gun mounted? I was wondering if it could have become a field modified German Tiger killer in 1943 in either Tunisia or Sciliy or is the gun too big for the SPG hull?

It was already mounting a 105mm gun-howitzer, so I don't think a 90mm AAA would put that much more stress on the hull.

Mark

The M12 and later M40 mounted two different 155 howitzers on Sherman chassis, so I think, yes, a 90mm AA would be okay. Not to mention the M36 tank destroyer mounted a 90mm high velocity gun and it was based on the Sherman. And of course the M36B2 which was also a Sherman based 90mm gun armed ATG.

Mike Bunkermeister Creek
Bunker Talk blog

The U.S. army did develop a prototype 76mm Tank destroyer based on the based on the same hull as the M-7 "priest", called the T-40. However, the project was terminated in April 1942, sine the Tank Destroyer Board felt that the vehicle was too slow.

As Bunkmeister noted since the same hull was used for the M-7 (105mm spg), M-12 and M-40 I suspect that it would handle be able to handle the 90mm as well.

There was a 90mm GMC T53 which used a Sherman hull. It was supposed to be dual purpose AA\AT but the project got cancelled in May 1944. The Canadians also got a 3.7 inch AA on a Ram chassis

The problem would be recoil length and gun size if there was a problem. The 105 was a very short gun, and a 90mm AA gun was not.
-Kle.

KL Hall is right, it is a matter of coping with a long barrel that needs blanching and the length of the recoil. It wouldn't look too clever if the crew had to load the beast from outside the armoured hull as happened with that Italian 90mm gun on a tank chassis.

The Germans managed to mount an 88/L70 ATG on a PzIII/IV chassis (the Nashorn), so why not?

Balancing is much less difficult with a fixed hull (non-turreted) mount. The hull winds up front-heavy, but you don't have the problem of the turret swinging to point downhill every time you drive on a side-slope.

The M10 TD was originally armed with a 3-inch M1918 gun. It was later upgraded to carry a 90mm M1 gun (the M36 TD). Same hull, same turret ring. The only reason the M36 got a new turret was because, well, the M10 turret had always been a bit of a problem anyways (it went through 3 iterations in production), and if you're going to pull the old ones off to put in a new gun, why not just finally fix all the turret issues too?

As mentioned, the M40 TD was also originally developed with a 3-inch M1918 gun (sorry, not a 76mm gun) in a fixed mounting on an M3 medium tank hull. If the M10 could be upgraded from a 3-inch to a 90mm, I expect the M40 could have too. Why not? Sure, maybe it would have needed some minor mods … most upgrades do. But it should have worked.

The question is, why? The 3-inch gun in the M10 was a Tiger killer according to the boys in Ordnance. All the test data and specs indicated it could handle a Tiger frontally without difficulty.

There was no evidence from the fighting in Tunisia or Sicily that this idea was faulty. Probably because M10s did not have much opportunity to engage Tigers. So why would 90mm armed M40s have been any different?

Once the US got ashore in Normandy that all changed, and it was discovered that the 3-inch gun could NOT handle a Tiger frontally, much less a Tiger 2! But within a month of that conclusion being reached, the first M36s were issued to units in ETO.

So a 90mm armed M40 might have eventually become salve to the bruised egos of modern US-centric wargamers, but they would not have mattered one lick in WW2.

-Mark
(aka: Mk 1)

The T53 transposed the engine compartment forward and the gun to the rear – I assume to reduce the overhang \ balance problem

It would have worked as a stopgap model, but a definitive version would probably have involved moving a few things around to make for a better-balanced model.