The difference between the FSN and NSN is simple. The FSN looked like this. 6115-234-5666. The NSN looks like this. 6115-00-234-5666. About the middle 60's, we ran out of numbers. AND we wanted to have our NATO partners also in the logistic system. SOOOOOOOOOOOOOOOOOOOOOO, we added the "00". AND the other country's also got into the act. 00 and 01 means the part comes from the USA. 12 means its from Germany. And so on. If you have a parts TM so old that it has only FSN's, and want to try and see if it has a NSN, simply add the two 00's. If it was a part that was carried over, it will come up.Homework report : Now to learn the difference between NSN (National Stock Numbers) and FSN (Federal Stock Numbers), and how to find them in reverse process.
Seems like the numbers in the manual and ordenance overview are NSN. Look for the 2320-192 by the picture.