MK108 impact on ground targets?

[kool kitty89]

Mineshell type thin-walled HE projectiles were (are?) used in the British 30x113B ADEN ammunition, and I believe the French DEFA as well. Either it was drawn-steel similar to the German manufacturing method, or just very thin machined steel stock, either way the capacity seems similar to the German rounds, at least relative to the shorter, lighter projectiles.

International Ammunition Association {iaaforum.org} - View topic - 30x113mm Sectioned

PHOTO GALLERY

The old 23 mm Madsen HE round also seems to be of a mineshell type construction, but again that might not entail using drawn steel cases but some other method allowing thin walls.

 

[Kryten]

They adopted the mine round with the Mauser cannon, which is what the ADEN and DEFA are based on, post war testing found the rounds to not be as effective as anticipated, ricocheting off oblique targets and not producing the required destrucive effect.

The mine shell was changed for a heavier round , fired at a higher velocity with greater fragmentation, the mine concept was dropped and has not been used by any cannon manufacturer since!

 

[Shortround6]

Some of it depends on technology, and some depends on physics. Mine shells can work with a certain grade of steel and certain manufacturing process at a certain velocity. Shell walls have to be strong enough to take the pressure at the back end while supporting the heavy fuse in the front without buckling. This is harder to do with high velocity shells with larger powder charges (higher pressure) and usually requires thicker shell walls. If your fabricating and metal alloys are good enough you can use thinner walls at a higher velocity than someone else using cheaper metal and/or different shell body manufacturing techniques (including heat treatment).
A lot of work was also done late war and post war to match the explosive to the specific shell body material (and processes) to optimize fragmentation. You need the right amount of brisance to the right material to get the size fragments you want. To much
Brisance can give you a few big pieces and lots of tiny pieces, shell body has literally shattered Too little and all you get is a few really big pieces and not many little ones, shell body has split open and vented the pressure before the body has had a chance to break up in the desired number of fragments. Tougher or more brittle shell bodies can be used with the same explosive to change the effect.
Comparing ammo/shells from 10-30 years after WW II to WW II ammunition needs a lot of care as so many 'details' could have changed. Even (or especially?) things like fuses. British changed from a brass bodied fuse to an aluminium bodied fuse for 20mm Hispano ammo and saved around 14 grams of total shell weight (over 10%) which allowed for higher velocity with little or no change in operating pressure. Also no change in target effect as you could change fuses on existing ammunition( not sure it it was done but it was possible. )

 

[Kryten]

What I have found interesting in modern design is how much attention is paid the fragmentation field density, it appears a larger number of smaller fragments in the envelope is the optimum for causing damage over a greater area, I'm also a little surprised just how far these fragments carry their energy!

I recall reading the late Gerry Bulls work on this, his 155mm artillery round produces something in the region of 3700 high energy fragments.

 

[kool kitty89]

Shorter shells of the same caliber would withstand higher velocities better, wouldn't they? (both due to the different dimensions -and particularly shorter overall straight-walled section- and the fact that the lower mass alone would allow for a velocity increase with a similar powder charge, though you'd really want a combination of shorter projectile and increased powder charge -which is more or less what the ADEN round did compared to the MK 108, with rather similar external dimensions and overall length of assembled cartridge, but a larger portion used by the case and propellant combined with a shorter, lighter projectile)

I'd think that more conical, tapered shells would be stronger on top of having superior ballistics. (plus they usually used more compact, lighter fuses and put less of the weight at the front of the projectile)