30 X 138 Experimental. USA.

[SG500]

This ones got me puzzled.
Its a 30 X 138. The rim is 44mm and the projectile length from the top of the case to the tip of the projectile is 133mm.
Its listed as an unknown round made in the USA in about 1970.
The projectile is crimped into the case and the driving band is also mainly crimped in.
Does anyone have any further information on it.
All INERT and empty etc.
Thanks.
Dave.

 

[SG500]

Anyone out there have any ideas on this one?
Dave.

 

[Chris 42 RQ]

Mystery item

A real mystery item SG500-got me baffled !

 

[SG500]

Just bringing this thread to life and wondering if anyone has any information on it?
Dave.

 

[Big Al]

Tony Williams on his web site quotes a 30 x 138 exp 1960s HS Type 836 AFV with a 42.7 mm rim. Possible?

I think it is listed in Vol 1 of de hek's book. The book lists a 30 x 138 Experimental USA with a rim of 44.3 and the drawing looks like the picture. The reference in the book is 30-138-01 and the drawing is on page 122 of Volume 1.

 

[SG500]

Tony Williams on his web site quotes a 30 x 138 exp 1960s HS Type 836 AFV with a 42.7 mm rim. Possible?

I think it is listed in Vol 1 of de hek's book. The book lists a 30 x 138 Experimental USA with a rim of 44.3 and the drawing looks like the picture. The reference in the book is 30-138-01 and the drawing is on page 122 of Volume 1.

Thanks Big Al, yes I have the de hek book and the drawing is of this type of round, the trouble is that's as far as it goes, no more information on this. I'll check out Tony's site, from memory the HS836 is different.
Thanks again,
Dave.

 

[Big Al]

This cartridge may be mentioned in the paper "Historical Development Summary of Automatic Cannon Caliber Ammunition: 20-30 Millimeter"
Author: D. M. Davis; AIR FORCE ARMAMENT LAB EGLIN AFB FL.

Unfortunately I have a pdf of this paper and the plates/photos are useless AND the author does not give detailed dimensions on the rounds described. Maybe someone has a better copy of the paper.

 

[SG500]

This cartridge may be mentioned in the paper "Historical Development Summary of Automatic Cannon Caliber Ammunition: 20-30 Millimeter"
Author: D. M. Davis; AIR FORCE ARMAMENT LAB EGLIN AFB FL.

Unfortunately I have a pdf of this paper and the plates/photos are useless AND the author does not give detailed dimensions on the rounds described. Maybe someone has a better copy of the paper.

Thanks Big Al, what page is it on? I've got a paper copy of the report, a great read it is too, but can't find the round in there. Photos are poor on my copy too.
Ta,
Dave.

 

[Big Al]

Figure 9 page 32.
Section IV page 14
Section XIX Part C page 158

Again this paper is difficult to use since it has no tables, no dimensions and the photos on my copy are unusable.

 

[SG500]

Figure 9 page 32.
Section IV page 14
Section XIX Part C page 158

Again this paper is difficult to use since it has no tables, no dimensions and the photos on my copy are unusable.

Thanks for that, I may be wrong but the rounds in fig 9 look a lot like Gau 8 based rounds with 170 to 172 case lengths, this one is 138 case length, its a lot shorter, I'll keep searching though.
Thanks again for looking.
Dave.

 

[Big Al]

If you ever find a "T" number or the gun it was intended for I have all 5 Volumes of The Machine Gun by Chinn in book form. He has a lot of the experimental guns developed in the US. Unfotunately he isnt up to speed on the cartridges as much.

 

[SG500]

If you ever find a "T" number or the gun it was intended for I have all 5 Volumes of The Machine Gun by Chinn in book form. He has a lot of the experimental guns developed in the US. Unfotunately he isnt up to speed on the cartridges as much.

Thanks Big Al, appreciated.
Dave.