This one you speak of , Did it shoot a caliber out of it also ? If so what size . Didn't the military use one similar to the specs of the old needle syringes .
http://t3.gstatic.com/images?q=tbn:tC67kGy79haUEM:http://itech.dickinson.edu/chemistry/wp-content/uploads/2008/04/syringes.JPG
The ones I saw also shot a .38 pistol cartridge.