Unknown 20x110USN projectiles

[Spaceinvader]

Hello Everyone,

I posted these on the IAA a couple months ago but unfortunately didn’t get any info back on them, I still have yet to identify them. All the markings I cannot find (like AFP) and official US ammo lists don’t include anything like either of these.

The strangest of the 2 is the 1/3rd cutaway that has a steel rod that runs the length of the projectile and comes out the bottom. The silver spacer inside is made of aluminum with the cap and main body also being steel. Most of the markings are missing with the cutaway portion but they seem to match the second blue TP projectile, remaining markings say “LOT 12 AFP”. The case it came in is a standard 20x110USN steel case, nothing fancy there. It could very well be a fantasy piece however it’s well made and old enough that the glue holding it together has begun to degrade and fall apart, in my thoughts atleast.

The second is near identical in construction to the other externally however without the steel rod, and painted blue (with what looks like red primer below the drive band. Consists of a steel body with a thin sheet steel cap and copper drive band. Markings say “20-MM MK.11-0 A LOT 12 AFP“. Again came in an identical standard 20x110USN case.

Maybe someone here knows!

Thanks!
Rhys

 

[US-Subs]

They look like a non-production item, possibly for testing feed mechanisms. Unfinished internals with no fins or provisions for fins, and the internal rod appears to butt against the windscreen, so I doubt it is for firing.

 

[Spaceinvader]

That could possibly explain the black one with the rod but doesn’t explain the blue TP-like one. There’s many variations of 20x110mm USN dummy rounds including ones made with rejected AP-T projectiles so seems strange to go out of the way to create a new projectile for testing feed mechanisms.

 

[US-Subs]

Agreed, but that doesn't seem to stop them from doing it over and over again, for that or other similar purposes. Years ago I had a friend that left EOD and went to work for Aerojet at Downy CA, doing medium caliber stuff. According to him they would be in the middle of a project and have a sudden need to try something different, the process was to simply fabricate a batch of trial pieces from whatever was available to see if the idea warranted further pursuit - they usually didn't request specific items from the supply chain to modify (at least initially) because that meant stopping for decision making, approval, logistics, etc. Instead just give it a try and see if we are wasting time. That doesn't mean that this is the case on yours, but there are a lot this type of pieces out there and it is impossible to identify for certain unless you have the provenance. I've got a bunch of similar strange ones, waiting for an ID document some day....