Are AR15/M16 high capacity magazines date stamped?  If so, where do they put it?  Is there any other way to tell the date of manufacture?

Thanks guys, just want to make sure I don't get screwed.

Matt,
Post bans are limited to ten rounds.  Only pre bans are high caps unless marked "For LE Only".  LE = Law Enforcement.

I knew the only legal hi-caps were pre '94.  But I am sure many of the magazines used by our military since have found their ways into gun shows and various ethically challanged dealers.

I try to protect myself, but who knows.  Are all post-ban hi caps marke LE only?

Thanks again.

M-16 MAGS ARE POST -BAN AND PRE-BAN DATED.
I HAVE A 4-'92 30RD MAG THAT IS LEGAL. THE DATE IS ON THE LOWER 1/3 LEFT SIDE OF THE MAG. IT IS LEGAL TO OWN. BUT AFTER 1994 YOU CAN NOT POSCESS ANY 30 RD MAG DATED AFTER THAT DATE. SO, YES THEY ARE BOTH DATED.

I've seen many military mags with dates stamped on the outside of the magazine (on the side). It usually has the month & year (i.e.;7 98). Many were at gun shows being sold as prebans.

I was refinishing a preban mag this weekend & found a date stamped inside. The date couldn't be seen until the finish was removed.

Okay, now I am getting a little worried.

I have on 30 rounder, that I cannot find a stamp on anywhere.  The same goes for both my 20 rounders as well.

any ideas?

I must admit, being relatively new to the AR that I bought them all at a gunshow.  Paid 10 dollars for the 30, and 15 for both 20s.  

I have 30 USGI mags and none of them are marked. None of the mags that the Marines issued me are marked, with the exception of one "LEO/Military use Only."

Just wondering - Is it legal for me to use that in my AR? I'm not sure if it is, so I always keep it in my wall-locker...

I am an FFL dealer and believe that I know some-thing about AR-15 mags.  None of the pre-ban AR-15 or M-16 mags were ever marked with a date to my knowledge.  The so-called post-ban magazines that hold more then ten rounds MUST be marked as
"LE" for Law Enforcement only. If your 30 rnd. mag HAS a date - it is probably stolen from some military warehouse/National Guard Armory, since dated magazines are being produced only for either the LE or military authorities, and there is no legal authority for resales to the general public.

Insofar as ethically challenged FFL dealers are
concerned, there is no problem with having M-16 mags that were made under military contracts. You will often find such magazines new "in the wrapper" with clear indications that the magazine was produced with military sales in the mind of the manufacturer.  Such magazines were often sold directly to dealers by the manu-
facturers after the original military contract was filled ("overruns"). Think of M.R.E.s.

A magazine which is not marked as stated below is presumed to be of preban manufacture. It has been reported that some postban magazines were manufactured with just a date and were not marked restricted as required by law.

A preban magazine may be used in any firearm under federal law and if not restricted by state or local law.

From the ATF FAQ:

(O15) What markings must appear on large capacity ammunition feeding devices
manufactured after September 13, 1994?

Persons who import large capacity ammunition feeding devices manufactured after September 13, 1994, or manufacture large capacity
ammunition feeding devices must legibly identify each device imported or manufactured by serial number and other prescribed markings. The same serial number may be used for all devices manufactured or imported. Such devices
must also be marked "RESTRICTED LAW ENFORCEMENT/GOVERNMENT USE ONLY" or, in
the case of devices manufactured for export, "FOR EXPORT ONLY." Domestically
made devices must also be marked with the name, city and State of the manufacturer. Imported devices must be marked with the name of the
manufacturer, country of origin, and name, city and State of the importer. Persons who manufacture or import metallic links for use in the assembly of belted ammunition are only required to place the prescribed identification
marks on the containers used for packaging the links.

[18 U.S.C. 923(i), 27 CFR 178.92(c)]

I've seen many mags at shows with '91 & '92 and one even had '89 stamped on the outside.

The mag with markings inside that I refinished last night had "02 91" on one side and "K2 91" on the other. The "02" & "K2" were both 90 degrees to the "91." I looked at it again and the dates were probably visible before I removed the finish. I just wasn't looking for them.

I checked some more mags and didn't see any markings inside.