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20mm cannon round

navyman

Well-Known Member
Hello,
Can anyone tell me which cannon this round would have been used in? Is it an aircraft round, and what should the projectile look like? The projectile pictured was turned from my wifes kitchen broom handle, I just took a guess at the shape.
The headstamp reads 1942, RG, OeZ. I'm assuming that this means; Made at Radway Green, in 1942, and is for an Oerlikon?
Info gratefully received,
Regards,
navyman.
 

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OeZ

Your reading of the headstamp is correct, it is a 20mm Oelrlikon round.

Th Oerlikon was mainly a naval round, although it saw some use in Land service in the Polsten gun which was a simplified Oerlikon. The Hispano was the Air service 20mm.

Your projectile is a bit too long. see here for some Oerlikon colour coses and proportions of the proj.

Regards
TonyE

[ame="http://s120.photobucket.com/albums/o191/aoe276/?action=view&current=20mmPlateII.jpg"]20mmPlateII.jpg picture by aoe276 - Photobucket[/ame]
 
Many thanks Tony and Chris,
Now I can look out for a suitable projectile, and replace the broom handle!
Regards,
navyman.
 
20mm

Hi Navyman,
here is a pic of one from my collection,this one is marked OeZ R.H. 1943.
All the best Tony
 
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Hello All,
I have just recently come across another Oerlikon S type round to pair up with one I've had for years.I've seen quite a few loose cases but they have all been blown at the neck,due apparently to the blowback operation of the original gun.Did the S type rounds use exactly the same projectiles as the standard versions?
Chris.
 
Hello All,
I have just recently come across another Oerlikon S type round to pair up with one I've had for years.I've seen quite a few loose cases but they have all been blown at the neck,due apparently to the blowback operation of the original gun.
Correct - the cartridge is sliding in the extended chamber at the time of firing, so the shoulder is unsupported by the chamber and is always blown out.

Did the S type rounds use exactly the same projectiles as the standard versions?
The S Type was the standard version. There were three families of Swiss 20mm Oerlikons, originally known as Type F (firing 20x72RB ammo), Type L (20x100RB) and Type S (20x110RB). Only the Type S was used by the UK and USA. The only major user of the Type F and Type L was the Imperial Japanese Navy, who used them as aircraft guns and designated them 20mm Type 99-1 and Type 99-2 respectively. There's a brief history and family tree of the Oerlikon and related guns on my website here: http://www.quarry.nildram.co.uk/apib.html

Projectiles for the British 20x110RB Oerlikon were very similar to those used in the 20x110 Hispano aircaft gun round, but not identical - the Oerlikon's driving band is narrower, and there is slightly less of the shell body behind it.
 
Many thanks,Tony,I need to take a closer look at my 20mm rounds,I'm
getting Oerlikon mixed up with Hispano it seems,and have been for a long time!!!
 
Hi Navyman,
here is a pic of one from my collection,this one is marked OeZ R.H. 1943.
All the best Tony

Thanks for the pic Tony,
Having compared your pic with mine I can see the difference. My case looks 'blown' between the marks I've added. can you tell me which weapons in 20mm use blowback rather than gas operation? The second attachment is a comparison with the Hispano.
Thanks all,
navyman.
 

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I must have looked at the headstamp on the Oerlikon case I have at some time,but whenever I did,it didn't stick in my mind.I was somewhat surprised to discover last night that I've owned it for at least half of it's life.I'm assuming that it's for one of the Oerlikon guns that remained in British naval service for a surprisingly long time,as mentioned in Tony's article on these weapons.The case is headstamped 20/70 OER FAEX at the top,and L-01 1990 at the bottom,it would have been fitted with a rather more modern projectile,I guess,than the WW2 vintage example that it's got at present.
 
...it would have been fitted with a rather more modern projectile,I guess,than the WW2 vintage example that it's got at present.
I wouldn't bet on it...that last time any Oerlikon projectile was approved for British service was in 1944, according to Labbett & Brown's TAG on the ammo.

Some more streamlined projectiles were offered for sale by makers in other countries, but the old blunt-nosed ones also remained available (and still are, I believe).
 
I must have looked at the headstamp on the Oerlikon case I have at some time,but whenever I did,it didn't stick in my mind.I was somewhat surprised to discover last night that I've owned it for at least half of it's life.I'm assuming that it's for one of the Oerlikon guns that remained in British naval service for a surprisingly long time,as mentioned in Tony's article on these weapons.The case is headstamped 20/70 OER FAEX at the top,and L-01 1990 at the bottom,it would have been fitted with a rather more modern projectile,I guess,than the WW2 vintage example that it's got at present.
Please could you post a photo of the HS.
 
20 mm Oerlikon

A typical 20 MM Oerlikon Practice round, note the shoulder before firing.
 

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Does anyone know af a place that you can get the Oerlikon cases resized to pre-fired shape, I have several that are blown out and would like to get them back to original shape.
Mike
 
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