30mm-75mm US Military Experimental

In 1979 timeframe, the Armament Lab at Eglin AFB in Florida received a research task from the Army to examine the freeflight characteristics of long rod penetrators. There was a range at Eglin that was particularly suited for this work. The test gun was a Soviet 76mm Anti Tank gun rebarrelled to take the round pictured below:

This is a 1945 vintage 75mm case with a solid steel neck piece to reduce the caliber to 30MM. The projectile was a long 30mm steel rod that was held in place by four set screws in the mouth of the steel neck insert. My understanding is that there were either 3 of these cartridges made, or three that survived the test program. I saw the gun but have no idea what happened to it. This is probably the longest 30mm cartridge ever tested!!! That is a 9mm Para cartridge in the photo for scale.

Cheers, Lew

Lew, outstanding !

Is there any info on the overall length of this beast or on the projectiles?

EOD, I should have done that when I took the photo. It is 28.25" overall and the projectile is 12". It has a groove about an inch from the base to take the set screws.

Lew, thanks, great info !