Most of you, I think, know what is meant by a term “STANAG magazine”. For those of you who do not, it refers to a specification prepared by NATO which describes the dimensions of an AR-15 / M16 compatible magazine. An example of the usage of the term is in the Magpul’s Masada spec document (emphasis added) …

Multiple ammunition magazine capability is accomplished with unique lower
receivers to accept either the NATO STANAG (USGI M-16) or the Automatic
Kalashnikov (AK) magazine. Additional lowers receivers that accept other maga-
zine types are also possible.

I received an interesting email from Roberto, a NATO employee, who explained that despite the term being commonly used, the specification does not exist. Apparently the draft STANAG 4179 was never ratified by member states and therefor it was discarded by default. If you call up the NATO Standardisation Agency (Bruxelles) and ask them for the STANAG 4179 document they will tell you that it does not exist.

This slide comes from a NATO presentation …

So there you have it – STANAG 4179 does not exist! “USGI compatible” is a more correct term than “STANAG compatible” when referring to AR-15 magazines.

Many thanks to Roberto for this information.