30mm Shirgun Rounds

[EODGUY]

I thought I would send in some photos of various items in my collection in case someone has not seen the things before. Here are two assembled rounds and two empty cases from the U.S. Shirgun development program. This program began in the early 1940's centered around development of a 20mm aircraft cannon. The Navy let a contract to the Schirgun Corporation and somehow, inspite of the fact that was the spelling on the company letterheads, the Navy changed it to Shirgun and that name carried forth. A prototype EX 1 weapon was developed, but the program died in 1949, only to be revived in 1953, as both a 20mm EX 5 weapon and a 30mm Mk 3 Mod 0 weapon. The 20mm system used the standard 20mm Hispano-Suiza cartridges, but as you can see, the 30mm system went down a totally different path. The program once again was later dropped. The left hand 30mm cartridge is the elecric primed T268 round with an FAT32E1 case that is about 133mm long, a T306E10 projectile that was fired from the T168 gun under an Army parallel program. The next cartridge has a 119mm long electric primed case from the FAT32 series and a Practice projectile. I do not have the model numbers for most of the rounds components. The first empty case is 136mm long. The far right case is the original FAT32 case design and it is 123mm long. None of the cases have a headstamp. Unique rounds at best. The right hand cartridge is a 30mm DEFA round for comparison.

 

[SG500]

Nice rounds, thanks for showing them and for the very informative write up.
Are you able to answer Chris42RQ's query in post 10 of the following link? Why are some electric primed and others not?
http://www.bocn.co.uk/vbforum/30-x-136-t55564.html
Dave.

 

[EODGUY]

Reference the question about the different primers. Every Shirgun case I have is electric primed and no reference I have, and they are very few, talk about a percussion primer. There were several different reverse feed gun prototypes developed under this program though and it is certainly possible one or more were percussion primed. I only know of two case types that I have ever seen in official documents, the FAT 32 and FAT 32E1. The FAT 32 was used in the T222, T223, T224 and T225 cartridges, which unfortunately I cannot positively identify the individual projectiles used in the rounds. The FAT 32E1 was used in the T266, T267, T268 and T269 cartridges and again I cannot ID all them from my records. The T268 was a Ball loading with the T328 TP projectile. All were for reverse feed guns.

 

[SG500]

That's great, thanks for the additional info.
Dave.