Question re: American Sherman 75MM

I don't know how to properly ask this without sounding totally ignorant, but here goes.

Was there any particular reason why we fought through the war with a relatively short barreled, low velocity 75MM gun on the Shermans?

Were the Germans munitions manufacturing methods superior to ours (the 88 in particular but also the 75MM as used in the Panthers are what I'm basing this on) or did we make a conscious decision to go with a shorter barreled gun possibly to make the Shermans more maneuverable in tight quarters somehow?

I know the Panther and Tiger came later in the war than the Sherman, but I believe we continued to maunfacture the Shermans with the 75MM throughout the war, did we not? I know that the British had the upgunned 17 pounder 76mm Firefly, but the American produced M-4s went through the entire war with the outgunned 75, did they not?

 

Because at the time the Sherman was designed the 75mm M3 cannon was more than powerful enough to deal with the armor of the day. As it also had a very effective HE round it was considered a good choice for the Sherman and, even the M3 Grant / Lee. In terms of effectiveness the US reached the same conclusion as the Russians did with their T34: That the best tank gun was a field gun. Their 76/42 cal gun has almost identical armor and HE performance to the US 75mm.

If anything, the Germans started the war off being under gunned on their tanks and continued to be well into 1942. Their view to that point was to split the antitank and support functions between their vehicles rather than have a single battle tank. The Pz III was the antitank vehicle first with a 3.7cm then a short 5 cm and finally a long 5cm. The Pz IV had the support function with a short 7.5cm and a bit of antiarmor capacity.

The US 75mm M2 and M3 were based on the French 75mm field gun and were essentially adoptations of that weapon.

When the Germans recognized the need for a more powerful antitank weapon on their AFV their first choice was the already extant 8.8 cm 56 caliber gun. This went into the Tiger I. They also started developing newer AT guns notably the 7.5cm Pak 40. This gun in modified form became the 7.5cm Kwk L48 gun on the StuG III and late model Pz IV. The 8.8cm L71 was an adaptation of the unsuccessful Flak 41 gun.

The US went the same route. They adapted the 3" AA gun for the M10 and towed 3" antitank gun. Development of it was made into the 76mm M1 gun that went on late model Shermans and the M18. Then the 90mm AA gun was adapted for tank use on the M36 and M26 Pershing.

The British had the 6 pdr in development when the war started but it was delayed into service by their defeat in France. Production numbers took precidence over new equipment. The 17pdr followed. When the British adapted this weapon for use in the Sherman they had to make a great number of compromises in the installation. The US Ordinance people found these highly objectionable, and not without reason. Of course, there was the "not invented here" syndrome too and they did have their own 76mm coming into service.

The British also made some other improvisations. They bored out the 6 pdr to take a 75mm round and installed this gun on their tanks. In Italy the Churchill NA was produced using old Sherman guns and mantles installed upside down and heavily modified on Churchill tanks to give them decent HE firepower.

The US continued to use 75mm Shermans just as the British continued to use 75mm Cromwells and the Soviets 76mm T34 all the way to the end of the war. These were used because they were available and already in the production pipeline to supply to the troops.

 

Only thing to add to that excellent answer is that the lower velocity, HE oriented guns had a considerably higher barrel life, and the US in particular considered that important before the war and when they selected the M2 75mm for the Lee. While it might not sound like a significant problem once wartime production geared up, the design process took a couple of years in most cases and designs were employed that had their origins in a peacetime philosophy. Then it was as TA says in his final paragraph, 'let's not complicate things by changing too much' philosophy.

 

Inially the British and Germans both went for mixed formations with support tanks with low velocity guns and combat tanks with an AT weapon, the 37 and 75 German combination is roughly equivalent to the 40 and 3" British one. Late war the British re-introduced the concept, but with reverse proportions, by adding one Firefly to each M4/75 platoon . The Germans dropped the practice in mid 1940 with the 50/L42 that was a "medium velocity" weapon but kept the 75/L24 Pz IV in production and finally went for AT optimized weapons in 1942 with the 75/L43 and 50/L60. IIRC the HE round of the 75/L43 was the same as the one of the 75/L24 so they did not loose in HE performace like the US did with the 76mm gun. IMO barrell life was not really an issue as a tank was likely to be lost or sent back to the factory for major repairs before the barrell wore out even with the low life L70 and L71 weapons.

The US believed that tanks should not fight tanks, so they adapted the venerable "medium velocity" French M1897 field gun for tank use. They TD batallions were supposed to deal with enemy tanks so the specialized tank killers were deployed outside the standard armoured formations.

The soviets did play around with the AT tank concept a few times (T-34/57 and JS-1) and even with the support tank (BT-7A) but generally remained faithful to the dual purpose gun, but they required the GP guns to be able to deal with the most common German armour.

The "tank should not fight tanks" doctrine was finally proved to be a mistake after the war, with the increase of gun power and vehicle size and armour the AT gun were abandoned and the main threat was from other AFVs. But in 1944/45 there were more Pak 40 than Tigers around and the era of the MBT was still to come so the medium velocity guns remained useful though the crews will curse it if they had the bad luck of running into a "big cat".

 

A few other points to add. The notion of "tanks should not fight tanks" was not easy to live by, except when it was. Very often our armor was not fighting another tank but attacking infantry, pill boxes and breaking through to harrass the enemy's rear. Tank v. tank was not an every day occurence for tankers (studies showed it was less than the norm.) The 75mm HE round (as already discussed) carried by the Sherman served this purpose well.

From the experience of US tankers it was also shown that technology (i.e., superior gun or armor) did not win the battle in tank v. tank fighting but superior tactics. The big bad Panthers, which could be knocked out by a Sherman a typical combat range, were coming up short against M4/75's because their crews were poorly trained and their tactics poor. When the Germans invaded France in 1940 their armor was inferior to that of the French but their tactics definitely superior and they clearly won the fight. As "blitzkrieg" showed the best use of armor is in a combined arms assault...if you can.

Let's not forget that the Sherman was also upgunned with a 76mm higer velocity gun which, with the right ammo, had extremely high tank killing performance. This ammo was, unfortunately, in very short supply.

 

I dont know where you got the idea that the 76 "had extremely high tank killing performance", as it could only penetrate a Tiger under 200m, as the shell would shatter from 150-1100m. Its called the "shatter gap", and its due to the velocity of the gun. Only under 200m will the brute force of the round cause penetration.
When it comes to the panther, the regular APCBC will only penetrate the Panther turret at less than 300m, while the HVAP (which each tank was issued six per month) could penetrate the turret at 600m.
There were some panther tanks which were made with inferior armor on purpose, due to shortages. Most of them used magnesium as a replacement for other rare metals, and it showed. The 17 pounder could penetrate these tanks glacis, but the 76 still could not. You can easily find pictures of these penetration on google.
The problem with HVAP/APCR is that angled armor makes it far less effective. A typical APCBC round will be about 30-40% less effective against 60 degree armor, while the HVAP is in the area of about half as effective. Its the same thing with APDS, if you can hit the target at all.
When it comes to tactics, they are absolutely the most important issue. The thing is that the Germans were not facing many tanks which were vastly superior to their own like the Allies were in 1944. The western Allies had a far lower rate of death than the Russians in the T-34. The Russians lost about 12 tanks for every tank they killed with their own, while about six Shermans were lost for every tank they killed. The Sherman had the advantage of a better sight and its armor was quite a bit more resistant and less likely to break apart. The Sherman was also quite a bit less likely to burn than the T-34, except if the Sherman was carrying ammo in ways which were unofficial. There was a Sherman unit which banned its tankers from carrying ammo in any way other than standard, and only 1 in 18 tanks burned when hit. That is remarkably low for any tank.
Even though the Sherman was taller, slower, and armed with a weaker gun, it still managed to be more successful due to the vastly superior training of the troops. One of the main things was that the Americans fought with hatches open, while the Russians were buttoned up. The Germans always talked about how many Russians died in idiotic ways because they had their hatches down. There are dozens and dozens of stories about T-34 driving withing meters of German tanks and not seeing them. In one case, a Tiger in Narwa actually struck a T-34 with its barrel before backing up and blowing it away. The Tiger was in a Village at the time, and they most likely surprised the Russians with their arrival.
There was also the Issue of radios, where the Russians had almost none, while the western Allies had only one way communication from the unit commander to the other tanks, and the Germans had full two way radio in all tanks. This saved many Germans, and led to the deaths of many many Allied tankers.
So tactics and communication were very important.

 

Fiction.

 

To answer the OP more directly, the Americans created many prototypes which were superior to the Sherman, but the production was still pretty low and it was not advised to lower it any more.
If you check out the Sherman production, nearly all 75mm were build before 1944, with a total of 32k being built by the end of 1944. Only 3500 were built in 1944, so it was pretty low. In late 43 and 44 they built 7100 Sherman 76, just a little more than the number of Panthers. They did not produce this massive horde of tanks like most people think.
When it comes to Sherman replacements, they began about the same time the Sherman was accepted for servive. They had an entire series of tanks called the T-20 series, which were all armed with 76 and 75mm guns on every chassis except for the T-26 which became the M-26 Pershing. The T-22/23/24 were like smaller Pershing, they were all identical except for the transmissions, with the T-23 being gas electric hybrid. Many people say the Sherman 76 carried the T-23 turret, but in reality the same turret was used in the 22 and 24 as well. The T-23 was accepted into service but production was denied for many reasons.
The successor to the T-23 was the T-25, which was just like a small Pershing with a 76mm. The T-26 was a larger version of the T-25, but with a 90mm and much thicker armor.
The 90mm was also used in the M-36 Jackson, which saw far more combat than the Pershing. The M-36 was more common than the Tiger in actual combat. Its turret was taken from an earlier attempt to fit a 90mm to a Sherman. The 90mm and the turret from the Jackson were designed specifically to be able to fit into the Sherman, and if you look around you can find pictures of the 90mm sherman prototype.
There were actually just over 100 Sherman/Jackson hybrids, which were made in theatre and pressed into service. They used a standard M4A3 hull, unlike the m10 hull used for the Jackson. The difference is very obvious, as the Sherman has rounded sides while the pure jackson has flat but angled side armor just like the m10.
So the US wasnt totally sitting on its hands, it did field more 90mm armed tanks than the Germans fielded Tigers and KT. The Germans however had to split them among two fronts, and therefore the 90mm was much more common on the western front than heavy tanks.
When it comes to increasing armor, its really not worth it. It would have taken a huge tank to counter the much larger German tanks, it was a much better idea to give them larger guns to return the favor. The armor wasnt as bad as they say though, more than 1 in 20 rounds bounced, so they were not totally unprotected. They were nearly immune to the 50mm or smaller guns, which is why the Germans rarely fielded them after 1943. If the Germans had kept the Panzer III like we kept the Sherman 75, the numbers would have been vastly different.
In North Africa, the Sherman gave the Germans a nasty surpise when it showed up, Rommel actually lost a massive part of his tank force to the first large force of British troops in American tanks. It was probably his largest loss ever, and most likely the largest number of German tanks killed by the western Allied tanks during any period of the war. I dont know of any other time when western allied tanks killed more than a few dozen tanks in one engagement, let alone over 100.
So when the Sherman 75 and Stuart tank came out, they were anything but crappy. They were superior to any tank then fielded on the battlefield until the long barrel MkIV with the full 80mm of armor showed up in numbers, which was nearly a year later. You can see why the Allies thought so highly of the Sherman, I bet they were really surprised when they discovered their previously awesome tank was now the worse main tank in the world.
American armored fighting vehicle production during World War II - Wikipedia, the free encyclopedia

On a side point, the British fielded a TD much like the M36, which was the Achilles. It was a 17 pounder armed version of the M10, and it was very effective. The 17 pounder is actually ever so slightly better than the 90mm which saw service in the war. Only after the war did the 90mm ammo become good enough to surpass the 17 pounder.

 

Many thanks to all who responded. I knew from reading some prior threads that there is a lot of WWII knowledge on this forum and I sincerely appreciate all of your input!

 

"So when the Sherman 75 and Stuart tank came out, they were anything but crappy. They were superior to any tank then fielded on the battlefield until the long barrel MkIV with the full 80mm of armor showed up in numbers, which was nearly a year later. You can see why the Allies thought so highly of the Sherman, I bet they were really surprised when they discovered their previously awesome tank was now the worse main tank in the world. "

Pretty inaccurate assessment of events considering we marched through Europe quite effectively with the "worse main tank in the world."

 

There's a term I haven't heard in a long time. Prepare of an order of magnitude drop in credibility if you use it on some forums. There was a very vocal author of a particular set of wargames rules I believe that used to go about it ad nausium and clearly didn't really understand what he was talking about. It did get the term a lot of publicity and some believers.

 

AFAIK the Sherman saw first combat a few months later than the "long" Pz IV. If you wait for the up armoured ones for comparison why not the Tiger that actually saw first use earlier than the Ausf H?. There was little to choose between a Pz IVG and an early M4 in terms of tank killing capability, the better gun for the German and better armour for the US vehicle more or less cancelled each other out. But the PzIV was a 20 ton class tank the M4 a 30 tonner.
The M3 was a decent light tank but not that much better than a Pz 38t, a vehicle the Germans considered obsolete by 1942.

 

That's what I had read.

 

Slow and weak compared to what? M4 Sherman was a reasonably high performing tank in traversing rough terrain and did road marches exceptionally well. Also, objectively, 51mm of well sloped armor or 64mm of decently sloped armor was better than 80mm of no slope. It was the firepower differential between Mk IV and 75mm Sherman that made the later to appear weak in protection.

If 4th AD's experiences was any indication, their Shermans were usually able to outrace the Panzers to an ambush point or envelope German tanks before the later could retreat. Certainly the T-34-76 did not have a better gun than the M4, and sustained mobility was comparatively poor. German veterans of the South-Western Front complained to Albert Speer that American tanks were far more mobile than theirs (to be fair they only had Mark IVs).

I would not characterize Russian tank commander fighting bottoned up "idiotic"; that seemed to be an inherent weakness in the turret's design, wherein the TC must also aim the main gun, making it pointless to go out of the hatch.

I am of two minds concerning Pz. IV lang versus 75mm M4 tank; on the one hand, the Pz IV had much better long range engagement capabilities. On the other hand, American 75mm was able to deal with Pz. IV when hits were scored, and the Sherman was just so much more mobile and dependable that Pz. IV seemed routinely outmaneuvered when there was maneuver room for the Allies. When you get outmaneuvered, than armor and gun didn't really matter very much, and the Sherman's mobility was a direct cause for that maneuver edge.

Actually, if Jentz is to be trusted, Pz. IVs produced before to June 1944 was just as vulnerable to the American 75mm as Shermans to the German 75mm, insofar as typical combat ranges were concerned (under 1200 meters). Mark IV J might have better luck with its RHA protection, but lack of a motorized turret and bad armor composition probably was not compensated by marginal increases in armor protection. After all, the Pz IV had a big 50mm turret and a 20mm glacis that even a 37mm AP round could punch through.

Also, the myth that it took x number of Shermans to take out a Y number of Panzers should be discarded at once. O. Bradley made a comment that it took many M4 tanks to knock out a Panzer, but in context he was referring to the Panther and Tiger tanks against which frontal shots were ineffective, and he NEVER said all 5 would be lost. The group responsible for pinning down the Germans and attracting fire frontally often was shot out, but the flanking elements that dispatched the Panzer shouldn't take much losses.

If you look at the total tank losses in Normandy--4,000 Allied vs. 2,300 German--the kill ratio claims just does not make sense without recourse to extraordinarily discrepancies in reasons of tank losses, which we know to be false. Compound it with the fact that in Normandy the Germans were mostly fighting from the offensive and scored most of their tank kills by flank shots, it is unclear what type of tanks the Allies used would have contributed significantly to greater number losses. Percentage wise there was no comparison. The Germans lost as many as 2/3 of all personnel in their Panzer Regiments, a gruesome loss rate that few Allied armored units approximated.