The 90mm was far superior to both the 75mm and 76mm in punching through reinforced concrete.ChristopherPerrien wrote:
High ground pressure was a common problem for all Shermans, as side armor it is my recollection that later model Shermans had thicker "side" armor on the top half of the hull (above the track)track than Pershings(103mm to 85MM IIRRC) but the Pershings actual hull armor was thicker than the lower hull armor on Shermans.
You pretty much made my case for equal front armor protection , although I think the Perhsing was slightly thicker a couple mm's, IIRC.
Like I said,IIRC< Darrin posted some interesting figs on this somewhere way back, which I have not found yet. Give me some time to find that, and it was not just some "bs". off the net.
True, the capabilities in armor penetration capabilities to the 75/76 gun as opposed to the 90mm were "different", with thre 90 of course being better, but that I don't think matters much, as most concrete bunkers could defeat most rounds fired by either of these weapons . Big bunkers were really only suppressed by tanks , while other assets moved in for the kill. In respects to just flinging explosive at appertures or hitting them with an AT round , the difference between 75 and 90mm tank fire is not much different in effect to the receiver of such shells.
I.E. the 90mm Pershing was no better a "bunker buster " than the avg late model Sherman. And as far as avg battles would have went against the poorly armored and AT armed Japanese during "Cornet" the Sherman would have benn as effective as the Pershing , and the Sherman was lighter and there were alot more of them around and it was a more familiar tank and it was easier to both land , ship, and support them.
Now if you want to re-fight the "Western Front" I agree that it would have bene better to have a lesser number of Pershings than alot of Shermans on a number of occasions, but even in that scenario, the point is quite debatable.
Let me try to find those figs.
See:
Mobile Artillery vs. Jap Fortifications
OFFICE OF THE CHIEF OF ORDNANCE
WASHINGTON, D.C.
MAY 1945
http://www.lonesentry.com/manuals/mobil ... index.html
The 90 mm Gun Motor Carriages, M36 Series and Heavy Tank M26 (T26E3) provides a companion piece to the 155 mm Gun Motor Carriage M40 (T83) for attack on the type of targets described above.
The higher muzzle velocity gives a flatter trajectory and greater accuracy. This is helpful when small openings are under attack.
Three rounds of the C.P. M78 fuzed M71 H.E. Shell will perforate a 5-foot reinforced concrete wall while 6 rounds will perforate a wall 7 foot thick.
Against earth bunkers the round is also effective as it will penetrate 20 feet of earth.
The 75mm medium velocity gun on most M4 Shermans was found to be next to useless against Japanese reinforced concrete positions on Iwo Jima and against the old Spanish masonry fort in Manila (blanking on its name).
As a part of the conventional weapons tests for Project Sphinx, the Tank Destroyer command documented that the 76mm was better than the 75mm, but inferior to the 90mm gun for concrete and earth bunker busting.
This paralleled the performance of M-10 tank destroyers with 3-inch guns -- used in lieu of M-7 105mm SPM in an independent tank battalion-- at Kwajalein with the 7th Infantry Division.
If you are just shooting at the back or side of a bunker , Why bother with what-ever tank, firing 10 90mm or 20 75mms rounds? . In such cases, Bring up a ol' 155mm SP and with one round or two blow all those MF's to hell. It's what Patton suggested in his book. And he learned that from those Metz forts that caused him much distress. Cujo's to your link describing how effective the 155mm was against bunkers. Or just get an engineer and blow'em up.
Or what kind of armor they were shooting at and what range <100yds? wiki says 2.75" at 0 at 500yds.