Need help with Gerlich Projectile Identification

I acquired this projo at a small militaria show this morning and haven’t been able to identify it yet. Any help would be appreciated. The closest similar item I can find in my books is the HE slug for the 42-28mm L Pak. 41. But this one seems substantially larger in size.

Basic measurements are…

Top and bottom flange diameters…51.65mm

Windscreen diameter…37.1mm

Center body diameter…36.9mm

Overall length…149mm

This example has 8 holes around the top flange, unlike the 42-28mm which had 5. It has a similar screw-off windscreen (with 1.5mm pitch threads) but the aluminum dummy fuze or plug is much smaller than the AZ 5072 fuze shown in the manual. The inner cavity contains residue of a brittle, black creosote/tar type filler. The base has a female threaded cavity, presumably for a tracer, unlike the male threaded base of the 42-28mm type.

The only markings I can find on it are two small arrows on either side of the fuze plug wrench flats pointing toward the tip. Nothing at all anywhere on the body, but it’s sort of smooth and rounded like it was polished up at some time long ago, or was carried in someone’s pocket for a couple years. I suppose light markings could have been worn off or they were never there to begin with.

Any ideas? Did the Germans experiment with 52-37mm taper bore ammo? A German round without waffenampts? A U.S. experimental based on a German type?

Rheinmetall trials a lot of calibers from 7,9/ 5,97mm to 240/ 210mm.

The calibers 50/42 and 50/37 are well known.

What you have is a 5cm HE shell for the so-called “Rommel Gun”. The cartridge case was based on the 5cm PaK 38 AT gun, but the precise dimensions are not known. The gun was built and tested with troops, but not adopted.

The weight of the HE shell is given in my source as 730g and the muzzle velocity 1,481 m/s. Polte and HASAG were involved in ammo development. Krupp got involved in developing a steel-cored AP. The tungsten-cored AP projo was capable of penetrating 100mm/400m/60 degrees.


The projectile was made in both 5cm and 5.2cm. From your measurements, you have the 5.2cm (52/37). For the only information on it that I’m aware of, see “Von Flanschengeschossen und Wolframkernen”, by the late Manfred Stegmuller, pages 108-109. I have this projectile, but know nothing about it other than what is in his book. To the best of my knowledge, none of the cases for it have turned up.


Thanks to all for the information. I also received a few pages scanned from the Stegmuller book from a friend in France. I noted the example photographed in the book is credited to Cliff Carlisle so it appears there are at least 3 in the central/western U.S.

From the text, it appears it might have been tried in both the Flak and PaK modes. It would certainly be nice to figure out what it used for a case but if the man who wrote the book didn’t know and the REALLY serious artillery collectors don’t have one, I guess I won’t hold my breath waiting for one. Still surprised that it isn’t marked, though. Is your projectile proofed or marked in any way Jim? Thanks again.



My projectile is the one shown in the book.  I did a trade with Cliff some years ago.  There are no visible markings as mine has a heavy coat of olive drab paint, obscuring anything that might be there.  There isn't an inert filler in the projectile, nor does it appear to have had one.  Of course, it could have been removed with acetone.  The fuze in mine (incorrect but fits perfectly and matches the profile) is a 2cm Kpf. Z.45.