There was a lot of duplication of effort and missed opportunities, too. Add some pie-in-the-sky ideas, like the small calibre squeeze bore guns despite having the opportunities to do the similar job with classic guns, and there is lot to comment upon, and indeed criticize the powers that were.
This is quite true.
Some of the technical "solutions" were not really practical at the time. Tungsten carbide worked and worked well, problem was that nobody had very much of it. One book claims that many of the German tanks in Russia had 5 rounds or less in 1941. Which really calls into question the whole taper bore/tungsten carbide core weapons program from the start. If you can't supply the ammo in quantity why are you spending time designing/manufacturing the guns?
Even the US could not make tungsten cored ammo in large quantities (enough for more that 2-5 rounds per tank destroyer) in 1944. US and Britian could hope for increased supplies. The Germans could not.
Germans: Along with the squeeze bore guns, there is the 5cm conundrum - reinvent the wheel with two new guns and two new ammo types, initially one as a tank guns and second as an AT gun, despite having the option to choose from the 5 and 5.2cm guns that are a known quantity even before Nazis came to power. And then they choose 5cm as a new calibre for the new gun (13mm 'away' from 37mm, and 25mm 'under' 75mm), instead of going to 55-60mm, with appropriate loads to get the best out of that. Such a gun would've been a good fit on the AFVs, too, and a real threat to the numerous Allied nedium tanks like the T-34, M3 and M4, Matilda II.
Not trying more with the 600-700m/s 75mm guns in the AT role before 1941 was a missed opportunity.
The gun makers (companies) had a pretty good idea of what they could make using their machinery and using the materials of the day. 1935 offered large advances over 1915 let alone 1895-1905. The gun makers would base new designs off of old ones and try to incorporate new materials and manufacturing techniques. Most companies (at least large ones) were working on ballistics on test ranges. Getting somebody (government) to pay for lots of research was the hard part. Or to get the government to give realistic requirements. Pre WW II German 10.5cm howitzers had aluminum parts in the carriage to meet the weight requirements for towing (number of horses needed). That did not last long as they needed aluminum for aircraft.
As to caliber, the seemingly small jumps in size of the bore could mean large jumps it the weight of the gun/equipment. Basic gun design goes with the cube law. You can finesse it somewhat but basically the difference between a 5cm gun and 6cm gun is the difference between 125 (5 cubed) and 216 (6 cubed). This would assume same length barrels (in calibers) same internal pressures and other things being the same. This also applies to the mount/carriage/turret.
Modern (post WW I) barrel construction allowed for much lighter barrels than the barrels of the same performance built in the 1890s and 19
. So we have to be careful comparing guns to make sure they are of the same design era. The US 76mm tank gun was a great example of modern (late 30s) steel manufacturing and modern propellent technology compared to early 1900s. Design goal was to get the same ballistics (or close) as the 3in 1903 coast defense gun (by way of the 1917 3in AA gun). They got the desired ballistic performance in much, much lighter barrel using a cartridge of less volume.
Even Henry Ford had been persuaded to give up on the 1908 model T in 1927 start making new cars and engines in the late 20s and 30s.
Tell the designers what you want and let them try to make it happen without being constrained by old guns/ammo in warehouses/stockpiles.
The German short 5cm tank gun was a mistake. The only 2 things it really had going for it over the long 5cm was that the crew was less likely to whack the barrel against an obstruction (tree, telegraph pole, building) than a longer barrel and less need for storage space for a given number of rounds. That barrel overhang was really important to a lot of countries, design teams in the 1930s. Seems to have disappeared fairly soon after the shooting started.
Of course, the whole 37mm in the MK III fiasco for compatible ammo was a mistake. Turret on the MK III was adaptable to larger guns. How much large is the question.
For some reason it
seems that the tank designers could come up with new tanks faster than the gun designers could come up with new guns
By the time a new gun got into service there were new/larger tanks to shoot at. Some of this was not taking into account the actual time (issue of requirement to actual service use) of the tanks and guns in question and the appearance that the two different teams (Tank vs Anti-tank) weren't talking to each other even the same countries.
Insisting on towed 128mm and long 88mm AT guns, while skipping the more realistic 88L56, long 75m as well as the 105mm guns was a mistake IMO. Granted, having the heavy towed guns has it's disadvantages, but still.
Very true. They were not the only ones. The American and British monstrosities tend to be overlooked as they never got out of the proving grounds.
And the design requirements had changed. Instead of wanting small AT guns that could deal with 5-15 ton tanks of the 1930s many armies wanted AT guns that could deal with 60-100 ton (or more) tanks and now you had to come up with tow vehicles to match. A small truck was no longer good enough let alone horses.
British were not going to use a Bren carrier to tow a 17pdr.
Crusader hull/chassis. Granted the Allies had hundreds of old tank chassis that would still run. Moving 3 1/2 and larger AT guns with their crews/equipment and required ammo required as much thought and manufacturing as the guns themselves although often overlooked.
Standard German 3 ton 1/2 tracks with 4.2 liter 100hp engines are not going to cut it.
Some of the failed American projects even for the 76mm towed AT guns show so some of the problems. Attempts to keep the whole thing small/light lead to wheels being too small (poor towing) and the gun barrel too low causing the barrel to hit the ground while towing. Combat requirement for low silhouette conflicted with towing/transport requirement to get the guns to where they needed to be.
Germans knew they were working on the Maus tanks and were expecting the allies to do something similar (or at least something much bigger than Sherman and Cromwell) and with tungsten carbide off the table brute force was the easiest answer for penetration. American M-26 "heavies" when they got there, were not any better armored (if as well) as the Panthers of 1943.
nstead of the Pak 41, that used the addition to the barrel extension - why not make something that is a 55-ish calibre 75mm gun due to a full-bore extension?
Depends on what else was going on. Maybe you can machine the existing barrel to take a 12-15 caliber extension. But you need a cradle that can handle weight. Or stow the extension while towing and screw it on while emplacing?
And to get any worthwhile increase in velocity you need a bigger propelling charge. Which might require a new chamber and cartridge case. New cartridge case/chamber means you can't use the old ammo stockpiles any more. Or at least not as is. You can salvage the powder and projectiles for reuse.
A lot may depend on how much rework you want to do of existing guns or perhaps I have misunderstood and you are talking about a Pak 41 with a non-tapered barrel using full bore ammo. Some sources claim that some of the Pak 41 carriages were given Pak 40 barrels. Perhaps that is the best path.
