More German Squeezebores

**SG500** · 16th November 2011, 09:18 PM

Just a few photos of some of the German squeezebore projectiles I've got.

From left to right:

20/13 tungsten cored
20/13 prac
28/20 tungsten cored, sectioned to show core
31/18 prac
42/28 tungsten cored

Dave.

**whsammler** · 16th November 2011, 09:45 PM

Nice collection there. Here are a few of mine.

Glen
http://wehrmachtinternetmuseum.tumblr.com/
Follow me on twitter @WHINTERMUSEUM

**SG500** · 16th November 2011, 09:59 PM

Thanks.
Nice arrowhead Glen, the correct cases are hard to find.
Thanks for showing them.
Dave.

**EOD** · 16th November 2011, 10:00 PM

WHsammler, that 37mm is no squeeze bore.

**Slick** · 16th November 2011, 10:14 PM

And mine.

OrdHut 7 04 2011 071 (Small).jpg

**RichardB** · 16th November 2011, 10:32 PM

Really nice to see these Dave....other than the 28/20 I have to say I don't know a great deal about the usage of the others....can you elaborate development and usage??

Anyway, although not all German or even squeeze-bored!!...here's a picture of my "desktop", "cored" rounds (..and infact a couple aren't properly cored !!....ho hum!)
Eitherway, I'm sure Dave will appreciate it :-)....my favourite has to be the 28/20 with original ballistic cap and of course the littlejohns, both in correct case and perfect nick !

Cored Rounds.jpg

Glen - really nice to see your rounds too

Is there any more out there??

Rich

**whsammler** · 16th November 2011, 11:49 PM

EOD is my 3.7 a taper bore?? Or???
I thought it was a squeeze bore. You learn something new every day.

Glen
http://wehrmachtinternetmuseum.tumblr.com/
Follow me on twitter @WHINTERMUSEUM

**EOD** · 17th November 2011, 12:21 AM

WHsammler, yours is a HVAP (HC).
It basically goes back to the design of the taper bore projectiles but is for ragular barrels.
During the testing of the tapered systems the fired the taper projectiles through regular barrels to get an idea of the increase of effect of tapered bores and found out that the AP effect of taper projectiles fired from regular barrels was still better than full caliber regular AP shells. So these "arrow heads" got made resembling the general layout of the taper projectiles but being full caliber projectiles.

Sidenote: The Russians copied these in various calibers from 45mm up to 100 or even 122mm not knowing why they looked like this. Only later the Germans figured that the advantage of these was in the low weight in combination with a heavy core they dropped this high drag profile in favour of more aerodynamic shapes which led to the Panzergranate 40/1 design which also had "real" driving bands then. The Russians again followed after 1945.

**SG500** · 17th November 2011, 05:55 AM

Originally Posted by whsammler

EOD is my 3.7 a taper bore?? Or???
I thought it was a squeeze bore. You learn something new every day.

Glen
http://wehrmachtinternetmuseum.tumblr.com/
Follow me on twitter @WHINTERMUSEUM

Glen, the squeeze or taper bore projectiles have to squash in on themselves and exit the barrel at a smaller diameter. The result is the projectile comes out the gun much faster, much as water does when you squeeze the end of a hose pipe. Because it has been squeezed it is a good aerodynamic shape. If you look at squeezebore type projectiles (including British Littlejohn ones) you will see flanges that are easily deformable back into the body of the projectile.
With arrowhead projectiles if you look at them there is no way that they are going to deform in the same way. Your 37mm projectile for example has a flat base (I'm ignoring the tracer bit), as do any number of similar arrowhead projectiles (German 4.7 and 5cm and Russian 4.5, 5.7,7.6 and 8.5cm for example). If a solid piece of tungsten was fired it wouldn't go fast enough so the idea is to sit it in the middle of a projectile that in itself is lighter than a normal solid steel shot. They do this by making the arrowhead shape by in effect cutting the spare metal from around the projectile body just leaving the front and rear part of it to touch the barrel. The problem being it its not a good aerodynamic shape so although good at short range it doesn't travel well.
Just as a side note, the British littlejohns were fired from standard barrels with an adapter screwed on the end to squeeze the projectile. The obvious problem being if they wanted to fire standard HE rounds then they'd have to jump out the tank and unscrew the adapter, not something they'd always want to do in the heat of battle. It was found that the littlejohn rounds worked really well at short range without being squeezed, in effect they were working in the same way as an arrowhead round would!
Hope this explains things.
Dave.

**SG500** · 17th November 2011, 07:58 PM

Originally Posted by RichardB

Really nice to see these Dave....other than the 28/20 I have to say I don't know a great deal about the usage of the others....can you elaborate development and usage??

Anyway, although not all German or even squeeze-bored!!...here's a picture of my "desktop", "cored" rounds (..and infact a couple aren't properly cored !!....ho hum!)
Eitherway, I'm sure Dave will appreciate it :-)....my favourite has to be the 28/20 with original ballistic cap and of course the littlejohns, both in correct case and perfect nick !

Cored Rounds.jpg

Glen - really nice to see your rounds too

Is there any more out there??

Rich

Nice rounds Rich.

According to the book “Von Flanschengeschossen und Wolfranmkernen” by Manfred Stegmuller information on the 20mm one is as follows:
“KWK based on the MG 151/20. Various bullets in calibres 20/13, 20/14 and 20/15 were tried for a fully automatic Kw.K against light tanks and trucks. A muzzle velocity of 1500m/sec was achieved with the 20/13. This type probably did not come to troop trials. A whole series of various bullets is known”.

According to the book “Military Cartridges part 4” by W.D.de Hek information on the 31mm is as follows:
“A 3cm Mk-101 aircraft cannon with conical attachment was used. Both flanges of the projectile were made the same diameter (31mm) as the driving band of the standard 30mm Mk-101 projectile. The final calibre was determined by the diameter of the coned adaptor screwed on the muzzle of the barrel. Cones with a final calibre of 18, 20 and 22mm were used. Through the use of these adaptors it was theoretically possible to carry out all trials with a single weapon. The case was a lengthened version of the Mk-101 case and was brass covered steel. The projectile was, following normal procedure with German cartridges for cone-bore barrels, sunk into the case up to the front flange. The measurements of the case were 268mm long with a rim diameter of 38mm”

If anyone has a spare of the 31mm case I would be very interested in adding one to the collection, well, I can only ask

.

Dave.