20 X 102/RG Marquardt

[SG500]

This cartridge is an experimental one developed by Frank Marquardt over the period 1946-1950 for the American Navy Airforce.

The brass case has no rim or groove

The cartridges were "shot" into the chamber from a container with an electric primer in a much reduced head.

The driving band was specially designed driving band to absorb the shock of firing into the chamber and to prevent the case from buckling.

They are found with aluminium and brass cases.

The containers are linked with springwire links.

The photographs show the round inside the aluminium container and also separate, the case headstamp, the container head (empty primer socket) and the links.

All INERT and safe etc.

Dave.

 

[leeski]

thats a nice looking round dave does the head come apart

regards lee

 

[SG500]

Thanks Lee, you're as bad as me, the first thing I do is try and unscrew things!
The head doesn't come to bits. I understand its a TP type plug.
Dave.

 

[Tony Williams]

This was for the first version of the MK11 gun, which was weird for other reasons: an 8-chamber revolver with two barrels, driven by a mix of gas and recoil, and with barrels partly smoothbored. I think that Marquardt liked doing things differently just for the sake of it!

The production MK11 was modified to use conventional ammunition: the 20x110 USN also used in the MK12 (Hispano) which was unique to US naval planes in the 1950s and 60s. The gun was never installed in an aircraft, but came only in a gunpod. A remarkable performance - up to 4,200 rounds per minute. The USN dropped them long ago, but others may still have some.

 

[SG500]

Attached a few photos of a recent addition, the aluminium cased Marquardt. It appears to have a graphite coating on it.

All inert/primer oiled etc. All I need is the right projectile for it so if anyone has a spare........

Dave.

 

[EODGUY]

The Marquardts in my collection, but like everyone else I have no reporting or documentation on the series. From L-R a brass cased electric primed round headstamped FA * 49 (The * is a star), brass cased FA 50 headstamp, the same FA 50, but with the prokjectile pulled, steel cased headstamped EKCO X 51, aluminum cased *FA*48 with a T61E1 projectile (This round came from a trustworthy source who said it was a test loading of a standard 20mm projectile, but I have my doubts.), another supposed developmental round (dummy) for the Marquardt with a steel band in the extractor grove to fill it in???? headstamp is FA 50 and there is no primer pocket. Finally, three different aluminum carriers that were used.

 

[SG500]

Thanks Bob, REALLY nice! What is the case length of the last complete round on the right? Is is 110mm?
Dave.

 

[EODGUY]

Dave,

Yes, it is 110mm, forgot to add that!

Bob

 

[SG500]

Attached a few photos of a recent addition, the aluminium cased Marquardt. It appears to have a graphite coating on it.

All inert/primer oiled etc. All I need is the right projectile for it so if anyone has a spare........

Dave.

View attachment 68559View attachment 68558View attachment 68557

I finally tracked one down at last :tinysmile_grin_t:
Now the problem is getting it in the case, its a bit of a tight fit to say the least.
Does anyone have any tips on expanding the neck on aluminium cases? Brass is easy enough but I don't really want so mess up a super rare aluminium marquardt case.
Thanks for any advice.
Dave.

 

[EOD]

This seems to be a "inside case" driving band while the projectile on the aluminum case is the regular type. Sowith the case for your projectile should have a larger mouth diameter.

I always urge people to never "stuff" things together that were not put together in a factory as the combination created never will resemble the original and may even misslead future researchers (a wide spread male problem). Widening or altering case necks or any other components to make them fit for anything should not be done in any case as it will ruin the item (imagine that being done with archeological artifacts - nobody does it...).
Keep items as they are and document and research them this way and as what they do repersent, not more not less.

Please excuse if I sound like a teacher but I have seen too many unique items which habe been ruined by all means of "making it fit" and making it "look like new again". Too many people never do realize how much damage they are doing to items by polishing or repainting or what ever else they do just to have it "look good" (or what ever they think what good looking is).

 

[SG500]

This seems to be a "inside case" driving band while the projectile on the aluminum case is the regular type. Sowith the case for your projectile should have a larger mouth diameter.

I always urge people to never "stuff" things together that were not put together in a factory as the combination created never will resemble the original and may even misslead future researchers (a wide spread male problem). Widening or altering case necks or any other components to make them fit for anything should not be done in any case as it will ruin the item (imagine that being done with archeological artifacts - nobody does it...).
Keep items as they are and document and research them this way and as what they do repersent, not more not less.

Please excuse if I sound like a teacher but I have seen too many unique items which habe been ruined by all means of "making it fit" and making it "look like new again". Too many people never do realize how much damage they are doing to items by polishing or repainting or what ever else they do just to have it "look good" (or what ever they think what good looking is).

Don't worry its not getting "stuffed" anywhere just yet. The interesting thig is that both Bobs and my alloy cases have the same crimping mark that doesn't correspond with the brass cased Marquardt crimping, Mmm more research needed. The good thing is I have both of the types of projectile.
Dave.