I'm really into WWII era armor, which of course means that every other day I'm seeing claims that the Tiger I was impervious to the Sherman's 75mm all around. Of course I know at this point that the 75mm had a chance to penetrate the rear and side of a Tiger I but I always believed the front was fully impervious to the 75mm. Then I started hearing accounts that the Americans in WWII were often equipped with outdated ammunition, and the higher grade stuff only existed in small supply. I got curious and decided to look up the penetration values for the Sherman's 75mm M3 L/40 (seen in the second chart)
http://www.wwiivehicles.com/united-states/guns/75-mm.asp
And then looked up the Tiger I specifications.
http://wwiivehicles.com/germany/vehicle/heavy-tank/pzkpfw-vi-e-heavy-tank.asp
The Tiger's armor is noted as being 4 inches (101.6mm) and the 75mm M3 L/40 loaded with M61 APCBC is noted for penetrating 100mm at 500 meters. Which I guess means that if you got closer than 500 meters, you could penetrate the 101.6mm of armor with the Sherman's 75mm.
Thing is some other guy also went looking around and pointed out that the M61 APC round is said to penetrate 70-77mm of RHA. And after looking around to find the difference between M61 APC (Armor Piercing Capped) and M61 APCBC (Armor Piercing Capped Ballistic Cap) we came to the conclusion that they're the same round under different names, as all APC rounds have the Ballistic Cap. So now there's an M61 (APCBC?) round that has two different penetration values at 500m.
Now this isn't all that urgent, I honestly just want it to rub in the face of people the insist that THIS: https://i.imgur.com/0nj41RY.jpg is undeniable fact.
So I've come to ask, could an M4 Sherman armed with the 75mm M3 L/40 loaded with M61 APCBC penetrate a Tiger I at ranges under 500 meters?
There were six types of shell fired by the 75mm Gun M2/M3: M72 AP, M61 APCBC, M61A1 APCBC-HE, M48 HE, M64/M89 WP, and M88 Hexachloroethane (HC) Smoke
1. This is an M48 High Explosive shell. Prior to 1943, the shell was yellow with black markings. After 1943, the shell was olive drab with yellow markings. The fuze was silver.
2. This is an M72 Armor Piercing (AP) shot, the "standard" round fired by the 75mm M2 L/31 and 75 mm M3 L/40. It is a regular solid shot with no ballistic cap. As a result, performance degraded sharply as the distance increased. It was de facto removed from service by 1944, being even more useless agains Tigers than the M61.
http://i.imgur.com/vaCKJpy.jpg
3. This is an M61 Armor Piercing Capped Ballistic Capped (APCBC) shot. It is simply a normal M72 with a blunt ballistic "cap" and "windshield" on it.
http://i.imgur.com/E6tgxWa.jpg
4. The M61A1 was an M61 with an explosive filler, similar to the German Panzergranate rounds but the vast majority of the time the filler was removed and the rounds used as normal M61's. They otherwise resembled the M61.
5 and 6. The M88 HC Smoke and M64/M89 White Phosphorus shells were also used. I can't seem to find an easy picture of these shells, but the M88 resembled a tin can placed onto the standard 75 mm casing, and the M64/M89 resembled the M48. Both of these shells were painted grey with colored bands, as were all US chemical shells of the WWII period.
In his book M4 Sherman vs. Type 97 Chi-Ha, Steven Zaloga cites a penetration figure of 74-86 mm at 500 m for the M61 APCBC shell.
In his book M4 Sherman Medium Tank 1942-1945, Zaloga says the M61 APCBC could penetrate 68 mm at 500 m and 60 mm at 1,000 m
The ammunition penetration table I linked specifies a penetration of 76 mm angled at 30 degrees at 457 m (500 yards) for the M72 AP shot and a penetration of 66 mm for the M61 APCBC shot. APC and APCBC shot was developed as a way to defeat face-hardened armor, which would shatter normal AP rounds that were fired at higher and higher velocities to try and penetrate it.
Zaloga's measurements do not specify whether the armor is angled at 0 degrees or 30 degrees, or cite the exact figures for rolled or face-hardened armor. But from the table above, we could assume Zaloga's figures are for angled armor. Translated, these figures equal roughly 85-100 mm.
Based on this, we can conclude that it's pretty unlikely for the 75 mm Gun M3 to penetrate the Tiger's front armor of 100 mm angled at 9 degrees, (equivalent 101.25 mm) from the front, during combat conditions. More than likely, the shot would shatter, ricochet off, or literally become jammed in the armor.
Now, in order for the 75 mm Gun M3 to kill a Tiger by shooting it from the front, a lucky shot through the driver's view port (cringes) which was only a few layers of armored glass, or bow machine gun ball mount would be necessary. A shot through the mantlet is an even worse proposition, being that it is 120 mm thick. A shot through the gunner's periscope aperture could be made. This Sherman was disabled by one (Shot "9") Under combat conditions, the odds of a killing shot like this are very unlikely.
Remember that the famous Tiger 131 was "killed" by a puny 6 pounder jamming the turret ring, making the crew abandon the tank.
M4 Sherman crews would often use the HC smoke or white phosphorus rounds against Tigers or Panthers, shooting at the tank so that the acrid smoke would be sucked inside. It was prone to starting fires in the engine compartment when it contacted boiling hot oil and hydraulic fluid. The crew would then be promptly machine gunned as they exited the tank. A perfectly good tank with no crew is as harmless as a blown up tank.
Sources:
Sherman: Design and Development, by Patrick Stansell and Kurt Laughlin
M4 Sherman at War, Zenith Press, 2007
M4 Sherman Medium Tank 1942-1945 page 10, by Steven Zaloga
M4 Sherman vs. Type 97 Chi-Ha page 22, by Steven Zaloga
Sourced armor penetration table
http://amizaur.prv.pl/www.wargamer.org/GvA/weapons/usa_guns5.html
