whelm Posted March 6, 2016 Share Posted March 6, 2016 Same for the 3" they had done tests with the velocity ramped up and the pressure and the gun handled them fine. Heck the actual case had a distance wad in it, which would have made it easier to add more powder. The m62 at 2800 ft/sec wouldn't have been to shabby and I doubt it would have added much extra wear to the guns. Yep they were both typical early 20th century engineering...or over-engineering. The reality is what made the 17-pdr "better" was more propellant generating greater chamber pressure and Mv. Not rocket science. OTOH, I suspect greater Mv in the M62 would have led to more shattering and more premature fuze actuation. Probably could have taken it. An example is the 75mm M61, they did a number of tests to compare it to the German 75mm, even to the point they were firing the M61 out of the German L/71 in a panther. Shattering started at 2966 ft/sec and above for the M61. Compared to the German 75mm which remained intact up to 3269 ft/sec. Results of that study were "It is recommended that the design features, hardness pattern and the composition of the German armor piercing projectiles be studied for the purpose of improving American armor piercing ammunition." Link to comment Share on other sites More sharing options...
DougRichards Posted March 6, 2016 Share Posted March 6, 2016 it seems that the biggest fault was testing shell vs. US armor, not vs "german equivalent", leading to the problems with shatter etc.; everything else is secondary - as even if you increase MV with hotter propellant, shell would still suffer. Then again, Brits had the same issues in first half of the war. And APHE worked for Germans throughout the war. In the end it is a lot like with the 88mm gun. Even when the actual AT gunners preferred 50mm and 75mm, still the 88mm had bigger psychological impact both on enemy and own troops (made bigger booms, had cooler caliber...). And solved many of the issues by using solid shot. Link to comment Share on other sites More sharing options...
DKTanker Posted March 6, 2016 Share Posted March 6, 2016 Why is it so hard for you to understand the 3" M7 Gun was not the 76mm M1 Gun? I didn't say it was. I said, for whatever reason, whatever the excuse, there was no serious consideration given to fielding an M4 with a gun comparable to that of the KwK 40/L43 for the US Army until the summer of 1944. That in my mind would include both the 3" and the 76mm. I dunno why you're fixated on 76mm but still, there they were, according to some guy named Rich, sitting in England rusting away waiting for somebody to get serious about using them. Didn't have this ammo, didn't have that whatever available, that doesn't concern me because those are all rationalizations. Those are excuses to justify lack of seriousness.Maybe the problem you're having is one of reading comprehension. Eh, Tinkerbell? Link to comment Share on other sites More sharing options...
Panzermann Posted March 6, 2016 Share Posted March 6, 2016 Yep they were both typical early 20th century engineering...or over-engineering. The reality is what made the 17-pdr "better" was more propellant generating greater chamber pressure and Mv. Not rocket science. OTOH, I suspect greater Mv in the M62 would have led to more shattering and more premature fuze actuation.Would the projectiles have shattered with the increasd muzzle velocity on the US test armor plates? That might have woken up the ammunition board and shown the problem. Link to comment Share on other sites More sharing options...
Manic Moran Posted March 6, 2016 Author Share Posted March 6, 2016 Why is it so hard for you to understand the 3" M7 Gun was not the 76mm M1 Gun? I didn't say it was. I said, for whatever reason, whatever the excuse, there was no serious consideration given to fielding an M4 with a gun comparable to that of the KwK 40/L43 for the US Army until the summer of 1944. That in my mind would include both the 3" and the 76mm. I dunno why you're fixated on 76mm but still, there they were, according to some guy named Rich, sitting in England rusting away waiting for somebody to get serious about using them. Didn't have this ammo, didn't have that whatever available, that doesn't concern me because those are all rationalizations. Those are excuses to justify lack of seriousness.Maybe the problem you're having is one of reading comprehension. Eh, Tinkerbell? Given that M4(76) was trialled and ordered early enough so that 1,000 would be ready for the invasion of Africa in 1942, that doesn't seem that there was no serious consideration.It wasn't until the using arm said "we don't care if you managed to make it work mechanically, we don't want this inefficient, cramped thing which will make us less effective overall. Try again.' that the return was made to the drawing board. Given also that by Sept 43 the US Army had decided to stop basically all 75mm acquisition by mid-January 1944 in favour of an acceptable 76mm system, this also indicates some serious consideration. Link to comment Share on other sites More sharing options...
Rich Posted March 6, 2016 Share Posted March 6, 2016 (edited) I didn't say it was. I said, for whatever reason, whatever the excuse, there was no serious consideration given to fielding an M4 with a gun comparable to that of the KwK 40/L43 for the US Army until the summer of 1944. That in my mind would include both the 3" and the 76mm. I dunno why you're fixated on 76mm but still, there they were, according to some guy named Rich, sitting in England rusting away waiting for somebody to get serious about using them. Didn't have this ammo, didn't have that whatever available, that doesn't concern me because those are all rationalizations. Those are excuses to justify lack of seriousness. Maybe the problem you're having is one of reading comprehension. Eh, Tinkerbell? As I mentioned earlier, my Stupid-Shitometer tolerance level is at about zero. I think everyone probably understands why. Last time. The Medium Tank M4 was planned from the get go to have a 3" Gun. That proved impractical because of the size and weight of the gun, which led to development of the 76mm Gun. However, when tested in spring 1942 it was unacceptable to the Armored Force. Further design work resulted in an acceptable design in summer 1943 with production in January 1944. So the reality, as opposed to your fantasy, is that "serious consideration" was given to fielding a "gun comparable to that of the KwK 40/L43" and KwK/L48 for that matter, as early as September 1941, nine months before the German gun was deployed in a tank operationally. The other reality is they were in England prior to D-Day, 113 arriving in April and May. However, since you live in fantasy-land you can pretend that is just what some guy named Rich said. Edited March 12, 2016 by Rich Link to comment Share on other sites More sharing options...
T19 Posted March 8, 2016 Share Posted March 8, 2016 Ok Gentlemen. Rich and DT Tanker, you have 24 hours to clean up your posts and act, or your existence at Tanknet will be put before staff for remedial action. Tick Tock..... Link to comment Share on other sites More sharing options...
Richard Lindquist Posted March 9, 2016 Share Posted March 9, 2016 Was there a compelling technical reason why the US couldn't generate more HVAP than it did once the need became apparent?After all, 4 engine bombers were crossing the Atlantic every day in 1944 (load 'em up with HVAP). It seems that if the need was there and the ammo was being produced that more of it could have been brought to the front.Unless JCH Lee was involved!Problem with getting better ammo was that tank ammo sucked hind tit for allocation of tungsten. The Air Farce sucked up all available tungsten for machine tools. Link to comment Share on other sites More sharing options...
DougRichards Posted March 9, 2016 Share Posted March 9, 2016 About the only thing that could have been (maybe) done was the M4E4 solution used post-war for military aid, putting after all the 76mm gun into Sherman 75 turret - would need Armored Force change of heart though.On the other hand, it would not make much difference. In the hedgerows of Normandy vs. Panthers, 76mm still has trouble from the front (and so does 17pdr) and 75mm gun is more than enough from the flank. What would have made difference would be HVAP shot, but that is a different story. All in all, at best you'd end up with Firefly-like limited distribution and that is something you got available in real life as well. @Gorka L. Martinez-Mezo yeah, I know - the question was "why Israel did not go for the 90mm" and the ties to France (and, in the end, French guns doing same or better job) are probably the main reason. By that time I believe Israel had only the 90mm MECAR gun in stock, and that was a completely different beast and not worth shoehorning to M4 turrets when there were French 75mma nd 105mm guns aplenty. Some interesting photos of 76mm guns in '75mm' turrets here: http://the.shadock.free.fr/sherman_minutia/m4a3e4/m4a3e4.html "Kelly's Heroes" used them, no wonder the US Army denied their use! Link to comment Share on other sites More sharing options...
DougRichards Posted March 9, 2016 Share Posted March 9, 2016 Was there a compelling technical reason why the US couldn't generate more HVAP than it did once the need became apparent?After all, 4 engine bombers were crossing the Atlantic every day in 1944 (load 'em up with HVAP). It seems that if the need was there and the ammo was being produced that more of it could have been brought to the front.Unless JCH Lee was involved!Problem with getting better ammo was that tank ammo sucked hind tit for allocation of tungsten. The Air Farce sucked up all available tungsten for machine tools. The other issue is that one of the 'parent' guns for the 3" AT gun never went to Europe. The 3" used the barrel of the 3in AA gun with the breech of the 105mm howitzer M2, on a modified howitzer carriage. The 3" AA gun was basically used for training whilst the 90mm crossed the Atlantic. There was an AP round for the 3" AA gun, the base fuzed Shell APC M62A1. The same projectile was fired by the 3" AT gun. Any AP projectile designed for a US AA gun would have had a primary coastal defence role, against light cruiser type raiders and the like, rather than tanks. The story is more complicated than this off course, as the 3" AA gun was based on an earlier 3" coastal defence gun anyway, the 1898 3in seacoast gun. If the 3" AA gun had been used more widely then more 3" AP ammunition may have been available. Link to comment Share on other sites More sharing options...
Marek Tucan Posted March 9, 2016 Share Posted March 9, 2016 I think the 3" AA AP round was actually taken to the AA gun from the AT, not the other way around. The M62 was APCBC round, later than the plain AP and both with different weight than the naval AP Mk.29. Link to comment Share on other sites More sharing options...
whelm Posted March 9, 2016 Share Posted March 9, 2016 They did have a M4 with an M26 turret for testing. They also wanted to or did? (one source says they did) put a M26 turret on the M6 heavy. Yes, they did have an "M4 with an M26 turret", but it wasn't for "testing" it was for demonstration purposes only...and it was a T26 Pilot turret, not an M26 one. This was a one off and existed for all of about 24 hours in July of 1944. It was apparently done to demonstrate the practicality of doing so to BG Holly, Chief of the ETOUSA AFV&W Section, who was visiting DTA to see the T26 pilots and the M4A3E2 as he pursued his mission to get more tanks and more tank firepower to the ETO. The hull BTW is that of an M4 (105mm), which was pulled from the production line for the demonstration. No changes were made to hull stowage, it was never runn off the arsenal floor, and after the demonstration the two halves went off on their merry respective ways. Interesting report from the Canadian archives. "As a result of the successful employment of the M4A2E2 assault tank, It is understood that there is now a definite U.S. requirement for an assault tank. At the moment it appears doubtful whether this will take the form of additional M4A3E2s, the T26E5, or of a heavied-up turret and mount on a M4A3 hull with E8 horizontal volute suspension. In order to gain information as to the performance of the E8 suspension, a 2,000 mile test has been satisfactorily run on an M4A3 hull with E8 suspension, carrying a T26 type turret mounting the 90mm gun.The all-in weight of this trail vehicle was 102,000 lbs." Link to comment Share on other sites More sharing options...
DogDodger Posted March 10, 2016 Share Posted March 10, 2016 That's ~10K lb more than the combat weight of the M26 itself... Link to comment Share on other sites More sharing options...
DougRichards Posted March 10, 2016 Share Posted March 10, 2016 Sounds like an upgraded T14 - that weighed in at 92,000lbs, and only had a 75mm gun. Weighed more than the GMC M40 Link to comment Share on other sites More sharing options...
Panzermann Posted March 10, 2016 Share Posted March 10, 2016 That's ~10K lb more than the combat weight of the M26 itself...HVSS ist quite heavy. Do we have weights for the Sherman with torsion bars compared to one without? Link to comment Share on other sites More sharing options...
whelm Posted March 10, 2016 Share Posted March 10, 2016 (edited) They were simulating a heavy weight as well I assume with extra loaded weight on the tank itself, it was a test to determine how well the E8 suspension could stand up for a new type of M4A3E2 basically. The jumbo for example: Turret assembly complete with basket and gun mounting weighed in at 20,510 lbs for reference.Gun mounting complete with 75mm round in breech and 30 cal ammo in feed tray, 4008 lbsnew final drive assembly 11,275 lbscomplete vehicle un stowed 79,720 lbsfully equipped less crew, 84,600 lbscompared to Hunnicutt who lists Un stowed 77,500 lbs, combat loaded 84,000 lbsBritish noted it would be very simple to put the 17 pdr into it Weight comparisons of current turrets.M4 (75mm) turret weighs 4 1/2 tons,M4 (76mm) weighs 7 1/2 tons,M4 (17 pdr) weighs 7 3/4 tons,T25 (90mm) 8 1/2 tonsT26 (90mm) 10 tonsM6 (3-inch + 37mm) 18,737 lbs complete weight supported on the ball race of the turret. included in this total is 4,255 pounds for the 3" and 37mm guns complete in mount; 8,860 for the turret casting and 854 for the turret rings, moving and fixed. They had lots of ideas and tests to uparmour with the E8 suspension. example http://imgur.com/a/hi8ah Edited March 10, 2016 by whelm Link to comment Share on other sites More sharing options...
DougRichards Posted March 10, 2016 Share Posted March 10, 2016 That's ~10K lb more than the combat weight of the M26 itself...HVSS ist quite heavy. Do we have weights for the Sherman with torsion bars compared to one without? Sherman with torsion bars???? Even the proposed replacement fot the M4, that is the T20, still used HVSS suspension, as did the T25 Medium, which was a T23 (250 built but none in service) fitted with 90mm gun had HVSS suspension. The later T25E1 did have torsion bars, and weighed 35,194kg, It is considered that the T20 T22 and T23 contributed to improvements in the M4. As if the M4 that went to war in Europe and it was the M4 that was going to win that war. Link to comment Share on other sites More sharing options...
whelm Posted March 10, 2016 Share Posted March 10, 2016 That's ~10K lb more than the combat weight of the M26 itself...HVSS ist quite heavy. Do we have weights for the Sherman with torsion bars compared to one without? Sherman with torsion bars???? Even the proposed replacement fot the M4, that is the T20, still used HVSS suspension, as did the T25 Medium, which was a T23 (250 built but none in service) fitted with 90mm gun had HVSS suspension. The later T25E1 did have torsion bars, and weighed 35,194kg, It is considered that the T20 T22 and T23 contributed to improvements in the M4. As if the M4 that went to war in Europe and it was the M4 that was going to win that war. http://worldoftanks.com/en/news/21/The_Chieftains_Hatch_M4A2E4/ "A true weight comparison between the M4 bogie type and the M4E4 type was difficult to make, as the M4 type was completely detachable and fits onto a square hull. The M4E4 type was partly built into the hull and required a more complicated cross-section, making it difficult to determine what parts are intrinsically hull and what parts are suspension. The conclusion was that in spite of the heavier wheels, the M4E4 suspension was about the same weight as the M4 bogie type." Link to comment Share on other sites More sharing options...
Panzermann Posted March 10, 2016 Share Posted March 10, 2016 Why didn't they put a M4E4 and a regular M4A2 on weight scales with the same volume of fuel etc.? That should have shown the difference in weight? Link to comment Share on other sites More sharing options...
whelm Posted March 10, 2016 Share Posted March 10, 2016 E8 suspension vs Torsion rod suspension. http://imgur.com/a/8Djmb Link to comment Share on other sites More sharing options...
Panzermann Posted March 10, 2016 Share Posted March 10, 2016 E8 suspension vs Torsion rod suspension. http://imgur.com/a/8DjmbThanks. Link to comment Share on other sites More sharing options...
richard g Posted March 10, 2016 Share Posted March 10, 2016 I didn't say it was. I said, for whatever reason, whatever the excuse, there was no serious consideration given to fielding an M4 with a gun comparable to that of the KwK 40/L43 for the US Army until the summer of 1944. That in my mind would include both the 3" and the 76mm. I dunno why you're fixated on 76mm but still, there they were, according to some guy named Rich, sitting in England rusting away waiting for somebody to get serious about using them. Didn't have this ammo, didn't have that whatever available, that doesn't concern me because those are all rationalizations. Those are excuses to justify lack of seriousness. Maybe the problem you're having is one of reading comprehension. Eh, Tinkerbell? ................................. Last time nitwit. The Medium Tank M4 was planned from the get go to have a 3" Gun. That proved impractical because of the size and weight of the gun, which led to development of the 76mm Gun. However, when tested in spring 1942 it was unacceptable to the Armored Force. Further design work resulted in an acceptable design in summer 1943 with production in January 1944. ............................................. Which sums up a pathetic effort, thankyou. If the M4 was 'planned' (designed?) to have a 3" gun how come the 'planned' for 3" gun could not be fitted? Why the failure involving something so obvious? And then we have the timeline. No need to hurry here chaps, take your time, doesn't matter if the 76mm is not up to scratch you can try again. Bugger me This little quote sums it all up for me, Ike according to Bradley."You mean our 76 won't knock these Panthers out? Why, I thought it was going to be the wonder gun of the war.... Why is it that I am always the last to hear about this stuff? Ordnance told me this 76 would take care of anything the Germans had. Now I find you can't knock out a damn thing with it." But the revisionist intraweb experts know better than those who were actually there running the war. Like 'There were hardly any Panthers there so a bigger gun was not needed'. Link to comment Share on other sites More sharing options...
DogDodger Posted March 11, 2016 Share Posted March 11, 2016 HVSS ist quite heavy.With T66 tracks, HVSS adds ~3100 lb if we compare the weight of an M4A3(76)W and an M4A3(76)W HVSS. Link to comment Share on other sites More sharing options...
Manic Moran Posted March 11, 2016 Author Share Posted March 11, 2016 Which sums up a pathetic effort, thankyou. If the M4 was 'planned' (designed?) to have a 3" gun how come the 'planned' for 3" gun could not be fitted? Why the failure involving something so obvious? And then we have the timeline. No need to hurry here chaps, take your time, doesn't matter if the 76mm is not up to scratch you can try again. Bugger me This little quote sums it all up for me, Ike according to Bradley."You mean our 76 won't knock these Panthers out? Why, I thought it was going to be the wonder gun of the war.... Why is it that I am always the last to hear about this stuff? Ordnance told me this 76 would take care of anything the Germans had. Now I find you can't knock out a damn thing with it." But the revisionist intraweb experts know better than those who were actually there running the war. Like 'There were hardly any Panthers there so a bigger gun was not needed'.The Ike quote is also incorrect, as a number of "damned things" to include Panthers met their end at the other end of a 76mm or the ballistic equivalent 3". However, it's a little beside the point. You have to look at a couple of different things going on. The first question is if the US wanted to substantially increase the tank-killing power of their tanks, and I don't think there is any doubt that they did, or that that desire dated back to 1941. Whether they technically could do it or not didn't stop them trying. Cases in point the M5 and M9 tank destroyers with the 3" guns, which got to the level of standardization before realities set in that they just weren't practicable no matter how much of an improvement the gun was over the 37mm and 75mm then in use by TD Force. A new gun was necessary. M10 was a stopgap in the meantime, The second question is if they increased it sufficiently. I think it is fair to say that they -thought- they had. That their thinking did not match with reality is another question, lay the blame where you like on that one. The third question was of they were capable of building an even bigger gun, equivalent in performance to 17pr and, again, the answer is yes. That was the 90mm, which was a contemporary.. The fourth question is "why didn't they use the 90mm", and that becomes a judgement call. A trail version was built, equivalent to the 17pr towed, but it was just too big and immobile to be useful, according to the US thinking. The British, obviously, disagreed. Similarly, sticking a big stonking gun into Sherman was not going to be without its disadvantages. Yes, it would somewhat improve AP measurement and HE content, at various other costs. If the 76mm was mountable to greatly increase AP capability to levels thought to be sufficient without bringing upon itself the arrays of problems an even bigger gun would have added, then the decision to go with the 76 cannot be particularly faulted given what was believed at the time. Later British developments could prove instructive. When they built Comet, they sacrificed some penetrating capability for a gun which fit a bit better into the turret of the tank it was being mounted in. But when the parallel Centurion was being built, with its substantially larger turret, they went with the 17pr. This would indicate to me that the British were well aware that the Firefly design came with a number of problems related to the large gun in the small turret. Link to comment Share on other sites More sharing options...
DougRichards Posted March 11, 2016 Share Posted March 11, 2016 Which sums up a pathetic effort, thankyou. If the M4 was 'planned' (designed?) to have a 3" gun how come the 'planned' for 3" gun could not be fitted? Why the failure involving something so obvious? And then we have the timeline. No need to hurry here chaps, take your time, doesn't matter if the 76mm is not up to scratch you can try again. Bugger me This little quote sums it all up for me, Ike according to Bradley."You mean our 76 won't knock these Panthers out? Why, I thought it was going to be the wonder gun of the war.... Why is it that I am always the last to hear about this stuff? Ordnance told me this 76 would take care of anything the Germans had. Now I find you can't knock out a damn thing with it." But the revisionist intraweb experts know better than those who were actually there running the war. Like 'There were hardly any Panthers there so a bigger gun was not needed'.The Ike quote is also incorrect, as a number of "damned things" to include Panthers met their end at the other end of a 76mm or the ballistic equivalent 3". However, it's a little beside the point. You have to look at a couple of different things going on.The first question is if the US wanted to substantially increase the tank-killing power of their tanks, and I don't think there is any doubt that they did, or that that desire dated back to 1941. Whether they technically could do it or not didn't stop them trying. Cases in point the M5 and M9 tank destroyers with the 3" guns, which got to the level of standardization before realities set in that they just weren't practicable no matter how much of an improvement the gun was over the 37mm and 75mm then in use by TD Force. A new gun was necessary. M10 was a stopgap in the meantime, The second question is if they increased it sufficiently. I think it is fair to say that they -thought- they had. That their thinking did not match with reality is another question, lay the blame where you like on that one. The third question was of they were capable of building an even bigger gun, equivalent in performance to 17pr and, again, the answer is yes. That was the 90mm, which was a contemporary.. The fourth question is "why didn't they use the 90mm", and that becomes a judgement call. A trail version was built, equivalent to the 17pr towed, but it was just too big and immobile to be useful, according to the US thinking. The British, obviously, disagreed. Similarly, sticking a big stonking gun into Sherman was not going to be without its disadvantages. Yes, it would somewhat improve AP measurement and HE content, at various other costs. If the 76mm was mountable to greatly increase AP capability to levels thought to be sufficient without bringing upon itself the arrays of problems an even bigger gun would have added, then the decision to go with the 76 cannot be particularly faulted given what was believed at the time. Later British developments could prove instructive. When they built Comet, they sacrificed some penetrating capability for a gun which fit a bit better into the turret of the tank it was being mounted in. But when the parallel Centurion was being built, with its substantially larger turret, they went with the 17pr. This would indicate to me that the British were well aware that the Firefly design came with a number of problems related to the large gun in the small turret. I agree with you in many ways, but not completely. The British equivalent to the US towed 90mm AT gun was really the 32pdr rather than the 17pdr. The 'all up weight', at least according to Hogg (no, not omniscient) was 7,700lb. The 17pdr equivalent was 4,624lb, which was quite a bit lighter. The 32pdr, for which precious little detail survives, was 94mm (based on the 3.7in AA gun), and which was judged to be somewhat 'unwieldy', particularly in a mobile war. The German 8.8cm Pak 43/41 came in at 9,658lb which was quite a bit for a detachment to move around the battlefield, but in defensive situations could be accepted. The US equivalent to the towed 17pdr was the 3in AT gun, both in towed form weighing in around 4,500lb. Heavy, but not unmanageable. (And yes, Mr Picky, they did not weigh exactly the same....) But where the US put the 90mm gun into a tank destroyer, the British chose instead to place the 17pdr. In essence was there much to choose between the two at the receiving end? Probably not. Link to comment Share on other sites More sharing options...
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