Aces High Bulletin Board

General Forums => Aircraft and Vehicles => Topic started by: bustr on March 19, 2004, 08:09:14 PM

Title: 20MM MK.2 Info?
Post by: bustr on March 19, 2004, 08:09:14 PM
I have the shell from a 20 mm round I found rolling in the serf near my home in Oakland Califonia. The ID stamps on the base are:

N03N 20MM MK.2 1943

Does anyone have information about this make and brand of U.S. Military ordinace from 1943?

I keep it on my desk next to a small sheet of aluminum while I'm flying, along with my link of .50 cal, .30-06, and .303. Gives me a lot of respect for the guys who did this in WW2.:)
Title: 20MM MK.2 Info?
Post by: Karnak on March 19, 2004, 08:43:00 PM
I don't know if it is related, but the M2 20mm cannon is what the P-38 uses.  Its a Hispano Mk II.

Now, I don't know if that is related to the 20mm Mk.2 you have.
Title: 20MM MK.2 Info?
Post by: BenDover on March 20, 2004, 09:17:04 AM
This looks like a job for Mr. Williams.:cool:
Title: 20MM MK.2 Info?
Post by: Tony Williams on March 20, 2004, 09:43:58 AM
Someone called? :)

If you see a 'MK' rather than 'M' number on a US round that generally means USN rather than USAAF. I suspect that this is an Oerlikon AA case rather than a Hispano. They are much the same size, but the Oerlikon's rim has a smaller diameter than the body of the case; in the Hisso they are the same size.

I also suspect that the headstamp may actually read 'NOEN'. When found on 20mm cases, this stands for Naval Ordnance Engineering Laboratory, Dahlgren, Maryland.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and Discussion forum (http://forums.delphiforums.com/autogun/messages/)
Title: 20MM MK.2 Info?
Post by: Pyro on March 20, 2004, 10:59:09 AM
Quote
Originally posted by Tony Williams
I suspect that this is an Oerlikon AA case rather than a Hispano.


I have the same cartridge in my collection and I can confirm that it is for the Oerlikon and not the Hispano.
Title: 20MM MK.2 Info?
Post by: Pyro on March 20, 2004, 10:59:49 AM
Quote
Originally posted by Tony Williams
I suspect that this is an Oerlikon AA case rather than a Hispano.


I have the same cartridge in my collection and I can confirm that it is for the Oerlikon and not the Hispano.
Title: 20MM MK.2 Info?
Post by: BenDover on March 20, 2004, 01:58:30 PM
Wow, didn't know they had l33t back then :)
Title: 20MM MK.2 Info?
Post by: bustr on March 22, 2004, 07:22:09 PM
Thank you, yes I mis-read the headstamp..it is "NOEN". And the extractor plate is smaller around than the shell web base.

[QUOTE
I also suspect that the headstamp may actually read 'NOEN'. When found on 20mm cases, this stands for Naval Ordnance Engineering Laboratory, Dahlgren, Maryland.

QUOTE]

The extractor rim between the plate and web is encrusted and fused with sand. The round has been fired, but there is no pin strike in the primer. Inside looks like a Berden primer. Seems like there is rust staining from the primer pockets into the web base. Also looks like rust staining spots, or possibly 50 years worth of slow mineral electroplateing inside of the shell and spots on the outside.

:) :) :)
Title: 20MM MK.2 Info?
Post by: bustr on March 22, 2004, 07:31:57 PM
Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk)

I went to your website. In the photo gallery 20MM Cannon Cartriges to 1945 Part I.

20x110RB Oerlikon FFS (and HS.9) <----this is my shell case, or is a dead ringer. That is a very large projectile. Now I know why 20MM are so effective.

thank you for your help.:) :) :)
Title: 20MM MK.2 Info?
Post by: Tony Williams on March 22, 2004, 11:45:39 PM
Quote
Originally posted by bustr

20x110RB Oerlikon FFS (and HS.9) <----this is my shell case, or is a dead ringer. That is a very large projectile. Now I know why 20MM are so effective.

thank you for your help.:) :) :)


That's the one - and you're welcome!

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and Discussion forum (http://forums.delphiforums.com/autogun/messages/)