Shortround6
Lieutenant General
And accuracy well and truly sucked.
Dreyse bullets may have been composite rigid sabot and not discarding sabot?
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And accuracy well and truly sucked.One might note that the 1841 zündnadelgewehr or Dreyse Needle Rifle used a lead egg shaped bullet in a wrapped paper sabot. The standard Prussian infantry rifle until after the 1870 War.
Tungsten, even for tool steel (around 7% alloy in the steel?) or for tungsten carbide cutting tools was not common, despite known advantages for cutting tools due to cost/supply.You don't have a lot of APDS in the 1939/40 because people didn't designed and have it manufactured?
Only at a significant reduction in armor penetration.If one does not push beyond 1000 m/s with the APDS - and most non-AA and non-Navy guns will not in that time - one can do with hardened steel.
Steel.Tungsten, even for tool steel (around 7% alloy in the steel?) or for tungsten carbide cutting tools was not common, despite known advantages for cutting tools due to cost/supply.
Problems exist to be solved. Using the best part of the 1930s to figure out the details and intricacies is a far cry vs. trying to solve the problems within the months of a brutal major war.Problems are that a longer penetrator requires a quicker rifling twist. Quicker twists raise pressures slightly, Quicker twists may require different HE shell construction (heavier walls or better steel).
At short range you may be able to come up with acceptable work arounds.
A long range the heavy for it's size TC penetrator offers significantly better long range ballistics in time of flight/drop and penetration. Assuming you can solve the accuracy problem of the discarding sabot.
Sabotage?And accuracy well and truly sucked.
Dreyse bullets may have been composite rigid sabot and not discarding sabot?
The not very good at discarding sabot. Supposed to discard and often did, but not always. Very much a prisoner of the materials and manual skill of the paper coiling sabot maker. The bullet was supposed to fly free.And accuracy well and truly sucked.
Dreyse bullets may have been composite rigid sabot and not discarding sabot?
Steel.
Make the cores from steel at 1st (say, late 1920s as experiment, and by mid-1930s for service), and move to tungsten when/if needed & available.
A big hindrance to the development of high tech AP projectiles was the very real lack on need in the 1920s and 30s. Until the late 30s and the deployment of the Char B1 tank with it's 40mm armor (the B1 Bis didn't show up until early 1937) a decent 37-47mm gun with fairly standard AP ammo would take care of things. I am emphasizing decent as the German 37mm was not and neither were either of the French 37mm or the French tank mounted 47mm guns.Problems exist to be solved. Using the best part of the 1930s to figure out the details and intricacies is a far cry vs. trying to solve the problems within the months of a brutal major war.
Seem like the mid-power 75-76mm gun still had it's placeA big hindrance to the development of high tech AP projectiles was the very real lack on need in the 1920s and 30s. Until the late 30s and the deployment of the Char B1 tank with it's 40mm armor (the B1 Bis didn't show up until early 1937) a decent 37-47mm gun with fairly standard AP ammo would take care of things. I am emphasizing decent as the German 37mm was not and neither were either of the French 37mm or the French tank mounted 47mm guns.
A Czech 47mm has a decent chance against the side of a Char B1 Bis from the side at around 500 meters with standard steel shot.
It was interesting to fool around with advanced projectiles but the actual need was not there until the late 30s. And a decent answer to a 28-35 ton tank was a 1 ton AT gun and not a 1/2 ton gun firing rare metal (for it's day) shot. Germans got all caught up in the technical answer (AP40 Shot) which bit them in the ass when the Soviets didn't give up in late 1941 and the Germans started running out of tungsten.
If you are going to bet your ass on trick ammo you better have a good source of supply for the raw materials.
Navies had been working on better armor and better projectiles since about 1860An AT gun should be somewhat future-proof, like all the weapon types should be. Granted, the armies of the day were not having decades of the experience, but they can take a look at the development of ships and aircraft to see the pattern of ever-tougher targets appearing, as well as the meant to deal with these targets.
AP 40 was one thing, the whole side track with taper bore guns (28/20, 42/28 and 75/55mm) was a path that did not need to be followed.The AP 40 was a way of keeping the existing and future AT guns relevant. Perhaps it was a mistake that there was no APCR with the hardened steel penetration for the all of the guns, and see whet works?
Very true.AP 40 was one thing, the whole side track with taper bore guns (28/20, 42/28 and 75/55mm) was a path that did not need to be followed.
Steel does not work anywhere near as well once you are not fooling around trying to make grenade throwers (French short 37mm guns) into anti-tank guns.
What do you have to do to get a core weight close to the same as the Tungsten carbide core?
If you use a steel core you loose a lot of weight and you can't increase the velocity enough to compensate. The much lighter projectile will exit the barrel before getting the needed velocity.
As a real world check the 30-06 rifle cartridge has been offered with bullets from 220 grains to 100-110 grains from factories and Remington offered a 55 grain bullet in a plastic discarding sabot. The 220 grain bullets could hit around 2300-2400fps depending on barrel and powder. The 110 grain bullets did around 3300-3400fps and Rem claimed 4080fps for the sabot load. Not quite twice the velocity for 1/4 the bullet weight. It has about 80% of the energy of the 220 grain bullet which is also not quite optimal.
Most artillery follows the cube law. When you go from a 57mm round to a 75mm round you not only have the increase in diameter which gives you the increase in area being a square of the diameter but just about everybody increased the projectile's length in proportion to the increase in caliber so the 75mm shells will be about 30% longer than a similar 57mm shell and have 30% more weight per unit of frontal area which gives 30% more penetration at the same velocity. Another thing is that the extra 30% weight for the same frontal area is why the larger shells retain velocity better for long range work.
It is this weight to diameter that really screws up APCR rounds and why APDS with tungsten carbide beats the heck of regular plain steel at long range.
A steel penetrator doesn't work for crap in an APCR round for distance and even with an APDS out of a medium (2000fps with full bore shell) 75mm are you going to get any better performance than the 57mm AT gun with 2600-2700fps velocity?
Problem is that just about all of those hundreds or thousands of mid powered 75mm guns don't have..A mid-power 75mm, that we have in hundreds or in thousands, beats the cr@p of the high-power 57mm gun that we don't have
Advantage is that the most expensive part of the guns - barrel, cradle, locking system and hydraulic system - are paid for. Advantage is also that there are tens of thousands of shells in the warehouses, some, like the HE and shrapnel, don't have an equivalent in power in the 57mm bracket (let alone the 47-50mm). Even the AP ammo is there, or it will not be hard to make. Many countries even don't have the 57mm barrel-making machines.Problem is that just about all of those hundreds or thousands of mid powered 75mm guns don't have..
1. Sight suitable for anti-tank work.
2. One man gun laying, that is one man controlling both elevation and traverse but since................
3. Most of these guns have really crappy traverse, 8 degrees at the most and the French guns had 6 degrees?
4. A high gun shield or silhouette.
This is just the physical problems, some of which are not hard to solve, some are.
Tactical deployment problems, aside from the limited traverse.
Guns placed in the front lines, or within 1000yds of the front lines to shoot at tanks are too close to use as general artillery support. If they fire they revival their position/s are a prime target for counter battery fire (or being targets by 81mm mortars).
Guns scattered about as AT guns may not be hooked up to the field phones for even answering calls for general artillery support. Depends on time spent emplaced and a particular armies signals capability.
Guns doing general fire support are too far from the front lines to deal with tanks unless they have broken through and penetrated 3-5 km or more.
Having a few good AP shells can help the batteries defend themselves from being overrun but that is not really acting as AT guns.
The F22 gun was rated by for 1400g of propellant. The older guns were not, their max was 1080g; the 1400g charge was to be used there in dire emergencies.Germans grabbed the Soviet 1936 field guns because they were both powerful and they had 60 degree traverse. The Germans changed the elevation wheel over to the left side of the carriage for one man gun laying. The Germans did not try to convert any older 76mm field guns.
True, but most armies of the 1930s didn't have enough guns to equip the field artillery units that they wanted.Advantage is that the most expensive part of the guns - barrel, cradle, locking system and hydraulic system - are paid for.
In 1934 the French apparently believed that trucks were passing fad.
The French did not have the number of 75mm guns needed for the expanding French army of the mid to late 30s. Swiping the field guns to make AT guns out of them just moves the problems to a different area.
What would have been prudent was to make 37-47mm AT guns and at the upper end, something a little smaller and lighter than the 47mm they did make.In the 1930s era and French budget: would it be more prudent to them to make 105mm howitzers in order to have the surplus of 75mm field guns that can be turned into the AT guns, or to make 57mm AT guns while leaving the field artillery capabilities pretty much at the level of 1918?
What would have been prudent was to make 37-47mm AT guns and at the upper end, something a little smaller and lighter than the 47mm they did make.
an over 1000kg AT gun was not really needed in 1940 or even for much of 1941 and parts of 1942.
The 25mm AT gun was a bit too much gun (size and weight) for the actual performance and it was a single purpose gun.
The AT guns needed to be able to be moved by men (crew) at least for short distances and 1000-1500kg guns need very favorable circumstances for that to be possible.
France had several facilities capable of making all sizes of cannon. Perhaps duplication of effort but in theory they could select the best gun or combine features (with enough time), and not have to settle on one answer.
Different times and different uses. What you need/want in a gun that needs to moved by men in 1937-40 France is not the same as what is needed in North Africa in 1941-42 and especially what is needed in a 20+ ton tank.I'm glad that you find the not-so-powerful 47mm guns at your liking after all these years
Very true but but a 250g HE shell (give or take) makes a 610g HE shell (German 37mm AT gun shell) look like a power house destroyer of stone buildings and pillboxes/bunkersShoehorning the HE shell from the 25mm AA gun should not be that hard.
Which gun? the 75mm bomb thrower or the 47mm?A towed version of the gun installed on the Char B1 would've been interesting until well into ww2. Put the muzzle brake on, a light carriage, and let the shells and shots fly, while being well under 1000 kg, and possibly under 800 kg.
Soviets are in a class of their own. Just about everybody else was pushing past 1500kg with not so good 75mm guns. The French 75 was just over 1500kg for a gun that should not be towed by motor vehicles, had very limited traverse and limited elevation which limited range.If the AT gun is in the 1000-1500 kg range, this is already the territory of the better 75mm guns.
Different times and different uses. What you need/want in a gun that needs to moved by men in 1937-40 France is not the same as what is needed in North Africa in 1941-42 and especially what is needed in a 20+ ton tank.
Just imagine the 6kg shell from a 75mm...Very true but but a 250g HE shell (give or take) makes a 610g HE shell (German 37mm AT gun shell) look like a power house destroyer of stone buildings and pillboxes/bunkers
75mm bomb thrower?Which gun? the 75mm bomb thrower or the 47mm?
Some of the US conversions also involved new barrels and/or new recoil systems and some used modified/new breech mechanisms.
How much money do you want to spend?
France restarted mining of tungsten in 1939 (284 tonnes) after abandonning it in 1921 (much mining happened in WW1), but the invasion of 1940 prevented its growth, which instead happened postwar (500 to 900 tonnes a year) and especially during the Korean war. French Indochina was the main colonial supplier (553 tonnes in 1938), otherwwise France received tungtsen from the usual foreign suppliers, that is the Iberian Peninsula, North America and China (an agreement for over 6000 tonnes had been made in June 1940 but the Armistice cancelled everything).Tungsten, even for tool steel (around 7% alloy in the steel?) or for tungsten carbide cutting tools was not common, despite known advantages for cutting tools due to cost/supply.
Firing large lumps of it out of cannon barrels is a pretty expensive use. Germany was getting a decent percentage of it's Tungsten form Portugal. French access may have been better?
The Famous US 76mm APCR shot of 1944 was usually issued at rate of 2-4 rounds per tank by the "book". Some tanks didn't see any for a few weeks at a time but if they didn't see a Tiger or Panther for those days/weeks I guess it didn't make any difference.
It's clear that even the superior performance of tungsten carbide doesn't invalidate the merit of steel cores as long as long as your gun didn't achieve 900-1000 m/s with full-bore ammunition. In the case of Brandt 75mm, you're talking about a 53mm core at 966 m/s, making it possibly more powerful than 6 pounder full-bore ammo. Even when using a 640 or 700 m/s class 75, you could still go with a slightly heavier core (say 60mm) to stay around 1000 m/s. The advantage of subcaliber ammo is that going for lighter but faster rounds can yield performance increases without exceeding the limit of your recoil system, as momentum can be reduced or kept constant.A steel cored projectile fired from a Fench 75mm gun or it's equivalent still offers the increase of muzzle velocity and increased chance to hit a moving tank. With 900 m/s give or take MV (and obviously ever lower at 200-300-500-700m distances), it should be still under the velocity threshold for steel to shatter. Experiment with the idea and execution; if the shatter is still there, move to a bit heavier projectile to decrease the MV a bit. Experiment with tungsten tip and hardened steel shaft if/when there is enough of tungsten to be had.
A mid-power 75mm, that we have in hundreds or in thousands, beats the cr@p of the high-power 57mm gun that we don't have - most of the armies were reasonably well equipped with such 75/76mm guns already in the 1920s and 30s, but nobody have had the high-power 57mm guns. Most armies didn't even have the high-power 47 or 50 mm guns.
This is actually sorta the period when more mobile carriages for high-speed traction start development. That said this just means that traditional carriages were ok for 30kph while the new carriages would be good for 50-70 kph. For war mobilization, the French settled on the 105mm Mle 1935 by Bourges rather than the Schneider design, the latter was not produced that much.True, but most armies of the 1930s didn't have enough guns to equip the field artillery units that they wanted.
A lot of the left over WW I guns were not in good shape and many were scrapped in the years following the war with armies keeping the guns/carriages that were in the best condition.
Training used up some guns and different economic problems delayed or canceled improvement/refurbishment plans. US did better than others as far as mounting old guns on new carriage's. France planned to but didn't get very far. France also had a real problem with their artillery program. It took way too long for them to decide that the French 75 was NOT the "be all and end all" to the artillery question and that some 105mm howitzers might actually be a good idea to have in the army. Production of several hundred 105mm howitzers sucked up a fair amount of the French artillery budget in the mid/late 30s. In typical French fashion of the time production was both slow and split between two different designs.
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In 1934 the French apparently believed that trucks were passing fad.
France already prototyped low-velocity 75mm howitzers in the 20s and 30s so little need for using the B1's gun here, if the concept had been retained.A towed version of the gun installed on the Char B1 would've been interesting until well into ww2. Put the muzzle brake on, a light carriage, and let the shells and shots fly, while being well under 1000 kg, and possibly under 800 kg.
This is how they obtained the 37 and 47 casemate and then AT guns. The 37 used the Mle 1925 AA gun as a base, while the 47 used slightly modified Mle 1902 cases in new guns (esp barrels) to handle increased velocity that was more in line with the gun and case dimensions.There was no need to reinvent the wheel, especially once Navy gifted them the 47mm guns. Improve on these, modernize the 75s (a split carriage also means greater range), add some decent AP ammo and you're good wrt. the anti-tank means. A modern 47mm can be under 500 kg, while still being useful. Bigger guns can also do well when firing the HE and other ammo types, the small guns less well.
The British 47mm guns in the 1920s were pretty much 1880s guns that had the black powder propelling charges replaces by smokeless powder without change the ballistics much. They might have produced some new barrels but kept the old ballistics.I was alluding to the British Army taking the advantage of the 47mm guns that feature nowhere in the RN plans past the 1920s.
Just imagine 6-8 men on foot (or with 1-2 horses) trying to cart around a worthwhile number of 75mm HE projectiles.Just imagine the 6kg shell from a 75mm...
The 75mm in the hull of the Char B. It was only an AT gun because the German tanks used such thin armor.............and got really close to the French.75mm bomb thrower?