Alternative Cannons/Projectiles for German Tankbusters

[Silavite]

Something that has bothered me a great deal is the fact the while Germany's Tungsten supply was very limited, it seems that they were perfectly happy with making all of their anti-tank weapons mounted in aircraft fire tungsten cored shells.
Were there any attempts at making AT guns or ammunition that didn't use Tungsten cored shot?

 

[Shortround6]

Most of the guns had a normal AP shot or shell. They just didn't penetrate anywhere near as well. In the caliber range than most aircraft could use (under 75mm, well under) Normal AP rounds weren't doing the job needed so it was Tungsten cored shot or give up on the guns.

Normal steel alloys were very prone to shattering on impact at the velocities the Tungsten cored shot used so trying to use Steel cores wouldn't work.

 

[kool kitty89]

Did steep AP shot tend to be hardened or tempered? Full hardening would certainly make cores more prone to shattering while I'm not sure how tempers of various sorts might handle it. At some point they should be tough (and soft) enough to end up flattening and mushrooming against the armor plate and at least doing more damage than shattering would. (I'd think something along the lines of spring steel would have good elasticity properties for that sort of application)
I don't have a good understanding of the behavior of steel at those velocities though, so perhaps softer-yet-tougher steel may still tend to shatter under those stresses.

 

[Shortround6]

They had been "hardening" AP shot since the American civil war. It started with chilled cast iron. There was an 80 year 'race' between armor makers and projectile makers by the time of WW II. Plain hardened Alloy steel starts to crap out at around 2000fps which is why they had capped shot, A 'soft' cap over the nose of the harder ( more brittle) steel body. This combo tended to reach it's limit at around 26-2800fps. Now if you overmatch ( German Long 88 vs Sherman tank) you can push pretty much anything though. Sintered tungsten carbide will work at velocities over 4000fps. These are impact velocities not muzzle velocities which helps explain things.

 

[kool kitty89]

Wouldn't the BK-37 barely be pushing into those >2600 fps velocities at close range? The MK 103 pushed it a bit further though. The likes of the British Vickers S (Littlejohn ammo aside) were well below that, though not all that great for penetration given the 40 mm caliber. (perhaps still a decent trade-off for the germans with their shortages, especially if they'd developed a relatively light low/medium velocity Oerlikon/MK 108 style API blowback weapon in the 37-40 mm range and still push better RoF and velocity than the <2000 fps of typical Vickers S AP shot or at least be lighter, faster firing, and have smoother recoil)

I know there were some experimental light AP shot designs tested on the MK 108, but the loadings of that gun just seem too light to make that worthwhile.




Aside from that, if they were mostly using conventional heat treated high carbon steel for steel AP cores, there should have been some room for imporvement using higher strength alloys. Sure, those would include other strategically limited metals (chromium, molybdenum, vanadium), but it shouldn't be nearly as bad as using tungsten carbide. (and in fact, it would be similar to the high speed tool steels used for machining that might replace the superior carbide bits due to shortages)