couple of dumb 20mm questions

[smle2009]

Hi to all,
have a couple of questions re 20mm ammunition,the first one should be straight forward, was the German made 20x110RB Orelikon known as the Flak 28?
The next question is about a 20x101RB I picked up the other day was told it was a Swiss SEMAG round,but can't find very much info about it apart from the usual SEMAG took over Becker then in turn was taken over by Oerlikon and that it was only really ever put to use by the Japanese during WW2.
The projectile,probably a tracer, is the part that has me 'stumped'....looks to be more in the 'style' of French Oerlikon/Hispano projectiles than Swiss,has the wider drive band you would expect to find on a Hispano yet the diameter below the drive band is 18.5mm typical of what you would find with a Oerlikon projectile...it is also 1mm longer than either Hispano or Oerlikon from the drive band forwards.
The case has no headstamp and there are no markings on the projectile and I'm sure we can take it as read that it has been re painted at sometime!....any ideas or info on this one chaps...any photos of these in your collections would also be very helpful.

Cheers
Tony

 

[kahu1]

I have only heard the SEMAG cases in reference to the shorter Becker type, 70mm.
As far as i know the Japanese 101mm case was very much a straight sided (parallel) type case.
I suspect your case is from a clearing round, looks much like a standard 20mm Oe 110mm, but is actually only ~100mm.Does it have any head stamp?
Your projectile looks more like a Hispano with the wider DB,maybe another countries manufacture,ie Swiss,french?Possibly Finnish?

Bob

 

[bender]

only a shell from hispano(I use the translator, there can be divergences in transfer):tinysmile_classes_t

 

[smle2009]

Hi Bob,
they did indeed make a 20x101RB http://www.quarry.nildram.co.uk/an_introduction_to_collecting_20.htm the ref to 100mm I'm sure is a typo,no it's not Oerlikon clearing round,the case of these were shortened by removing part of the neck above the shoulder, and as previously stated the diameter below the drive band is 18.5mm as found on Oerlikons not Hispano.

Hi Bender thanks but you show normal 'run of the mill' 20x110 Oerlikons.

Photo is of 20x101RB next to a 20x110RB

Cheers
Tony

 

[kahu1]

Tony ,
I understand the SEMAG 101mm became the Japanese 101mm case/round,and as can be seen in the link provided was a more parallel sided case.
The 20mm Oerlikon clearing round was 10mm shorter than the standard Oe 110RBmm ,not by losing the neck but by lowering the whole shoulder 10mm.
See attached pic, A 20mm Oe 100RB clearing round with neck.Even though the 110RB case next to it is a fired one, and shows the blown out effect caused by the API system , you can still see the position of the unfired shoulder.



Bob

 

[SG500]

Nice bullet Tony.
Attached some info on semag.
The Hawkinson list has details listed a 20 x 102 RR
"20mm Oe Exp type? USA? Modified? 1.8mm Rim Groove. Shotenend 20 x 110?"
Dave.

 

[bender]

Add please a photo of a collum of a sleeve.

 

[smle2009]

Hi Bob,
I'm not suggesting this one is Japanese,which is slightly longer,I put the link on as you said you didn't know of a SEMAG 20x101RB...thanks for the photo of the clearing round..understand where you are coming from now:tinysmile_twink_t:,also I'm not saying it is from SEMAG,that was what I was told...my personal feeling is that it's Oerlikon manufactured anyway and later than SEMAG

Dave..rim groove looks to be 2mm but I have nothing to measure it super accurately:tinysmile_angry_t:

Bender...not sure what you are asking?....if you mean the headstamp it has none

Cheers
Tony

 

[bender]

Please, make photos of the bullet bottom.

 

[smle2009]

Hi Bender,
here you are,not a lot to see as it has no headstamp

Tony

 

[Tony Williams]

The Oerlikon "family" is shown in the photo in this article: http://www.quarry.nildram.co.uk/apib.html

The more slender shape of the 20 x 101RB is clearly shown.

 

[smle2009]

Thanks Tony,yours was the first site I looked at to try for an id...I think I ought to try and clear a few things up as it looks a few 'knickers are getting crossed here' :tinysmile_shy_t:.
Firstly I never said it was a SEMAG 20x101RB,that was what I was told when I picked it up,the profile of the shoulder would show it is obviously from Oerlikons stable who took over from SEMAG....Bob has a valid point about a Oerlikon clearing cartridge (20x101.3RB)but it has no headstamp and any I have seen do,the MkI has a 'normal service' headstamp and the Mk II has II added(often out of line with the rest of the headstamp)...the projectile seems to be a 'mongrel' of Hispano and Oerlikon with the wider drive band of the Hispano and the 18.5mm diameter of the projectile below the driveband which is very much a Oerlikon feature ???????

All the best
Tony