This information was originally posted on our forum by LDD. Please understand that LDD and or its staff are not firearms experts, law enforcement, lawyers, legal experts or anything of the sort so this information should not be taken as legal advice. The observations regarding date stamps on magazines described in this post are just that, observations based on examining several magazines and are not intended to be taken as absolute fact. As always, please consult a qualified legal expert if you are unsure of any laws or regulations.

Magazine Varieties:

If you are looking for a really durable, bomb-proof magazine, then I'd point you to the Chartered Industries (CI) and Imperial Defense (ID) steel 30 round magazines. These are NATO standard dimensions, but the ID mags were intended for the Brit's SA-80s. IIRC Singapore uses a mix of rifles that include M16 pattern and their own domestic bullpups. Both fit in properly spec'd US AR15s without modification.

Chartered Industries Mags:

Chartered bodies

Parkerized grey bodies

Chartered Floorplates


Chartered Followers


The downside of the CI and grey ID mags is the prebans shipped with blue followers that were complete crap. They were shaped like our green/orange followers, but made out of a plastic that has the consistency of a gummy bear (they would bow inside the mag body: bow in front = follower hangup; bow in back = bolt doesn't lock back on the last round).

I replace these blue followers with Magpul followers as a matter of conscience, before I sell them (they are that bad). The CI mags may require you to grind a little of the MP followers away before they will fit (front baseplate retention tabs on CI mags are oversized compared to USGI mags). MP followers fit the Imperial Defense mags without modification.

Imperial Defense Magazines (subcategories: Black and Grey):

Did some more research on these, including contacting some folks that used the black magazines for wildcat builds during the ban. I knew the grey ones were preban because I bought a batch during the ban (at "preban" prices too). Personally, I never encountered the black ones till after the ban but have since spoken with builders, who, as I said, used the black 30 round mags for wildcat AR builds.

Black Variety Imperial Defense magazines:

These are steel, with a smooth outside and inside finish and come with a stiff green follower that does not need to be replace in favor of a US green/orange follower (Magpul followers are still an upgrade worth considering though). IMO, the blacks are slightly more desirable due to the smoother finish which allows marginally easier follower travel.

ID Body

ID Body

ID Sticker

Note the "ENGLAND" sticker on the side of the magazine; both grey and black varieties came with these stickers, but they seem to adhere to the black finish better

ID Floorplate

Baseplate with manufacturer and origin stamping

Compare the weights below:

Black ID weight

Weight of Black ID Magazine

USGI weight

Weight of USGI Magazine

Grey Variety Imperial Defense Magazine:

These magazines were park'd inside and out, came with gummy blue followers, wrapped in stinky cosmoline coated brown paper stacks of 5, and featured unmarked baseplates.

Gray ID bodies

Note the areas where the "ENGLAND" stickers have peeled off (in the lower 2nd plateau behind the main corrugation rib). The brown markings are cosmoline build-up, not rust

Gray ID followers

Blue gummy follower (recommend end-users replace immediately before using magazines)

Gray ID floorplates

Unmarked baseplates

Gray ID weight

Weight identical to black variety

USGI Magazines without Date Stamps:

Black Teflon Body

Black Preban Teflon

The top of tier of USGI mags are Labelle/Bushmaster/DPMS that are teflon coated. BM mags were teflon coated grey, the other two are teflon coated in black (BM mags are more rare than the black variety, but not necessarily worth any more). Different colors, different baseplates, same manufacturer (Labelle). These are functionally the best of the USGIs, as they were coated inside and out and very slick (no follower hangups inside). Unfortunately these magazines are also extremely rare as they only went into production in June of 1994. That left only ~3.5 mo of production before the ban went up. They shipped with black followers. Most folks have never seen a teflon preban, but if you do get to handle one, you'll know instantly that it's a different breed from the regular moly-coated USGI.

The bodies of preban teflon mags were undated, but postban teflons manufactured by D&H (which eventually took over from Labelle) have the cage code "04TQ4" stamped on the bodies.

USGI Magazines with Date Stamps:

Next up are the date-stamped mags. These are standard USGI moly-coated mags that have date stamps on them (desirable for the reason that they "prove," as much as such is possible, the date of manufacture).

There are two categories of date-stamped magazines: external stamping and internal stamping. Only two manufacturers of USGI mags ever made preban mags with date stamping of any sort.

External Date

External Date Stamps

Center Industries made magazines with external date stamping on them. The stamping on Center magazines tend to be blurry and less crisp than Okay. They also feature the CAGE code "6P199".

Okay Industries (sometimes referred to as "Circle Kay," not sure which it technically correct, so take your pick), made magazines that spanned three eras:

  • Month only. Stamping on the inside of the magazine would be KXX on one side and XX on the other side. An example would be a magazine stamped 'K4″ on one side and "04" on the other side. This indicates April manufacture, but no year. Okay replaced this identification scheme with a full month and year scheme (KXX/YY). KXX stamped mags are often misidentified as postban magazines. Okay switched to the KXX/YY date code after the KXX scheme. So a postban magazine made in April of '04 would be marked "K04/04" and "04 04;" not simply "K04" and "04." Postban Okays also have Okay stamped on the body, along with an external date code stamp (see below for that formatting).
  • Month and Year (internal only). Stamping on the inside of the magazine would be KXX/YY on one side and XX/YY on the other side. An example would be a magazine stamped 'K4 86″ on one side and "04 86" on the other side. This would indicate the magazine body was stamped in April of 1986. Earliest magazine I've found in this era was 1986, though there could be earlier examples out there. Latest I've found is K03/91.

Photo Examples*:

Internal Date

This is a K01/91 internally date stamped magazine that has be cut open and unfolded to reveal markings

Internal Date Closeup

Close up of stampings

Internal Date Inset

Stampings shown right side up

Note the orientation of the baseplate locking tabs (green arrows). When viewed from the base of the magazine body, the markings will be always upside down. Since magazines bodies are composed of two independent halves that are welded together, it is possible to have a magazine that has different month codes. I have encountered one example where the year was the same, but the month codes were 1 month apart.

[*This magazine was irreparably and fatally dented. It's always sad to destroy a preban magazine, much more one that is verifiably preban, like this one, but it wasn't going to feed any more rounds in its life. At least this way it continues to serve in the cause of our freedom, now under the first amendment, rather than the second. And better mine, where I can get more than, one of you guys' mags in a ban state.]

  • Month and Year (external & internal). Same stamping scheme as above, internally, but also stamped externally with the month and year (X - YY, or XX - YY) and CAGE code "33710". Okay mags that are externally date stamped are also internally date stamped. Earliest magazine I've found in this scheme was 6/91, IIRC. So the switch from internal only to int/ext&int happened sometime in that period between March '91 and June '91.
MM/YY Example

Example (mags on left are Center, mags on right are Okay)

For obvious reasons of convenience, externally stamped magazines tend to command a higher price than magazines that are only stamped internally.

USGI Magazines Without Date Stamps:

Next are USGI manufacturers that did not date stamp their magazines. These are:

  • Adventureline
  • Center*
  • Colt (actually made by Okay)
  • Cooper
  • FN
  • Labelle
  • Okay*
  • Parsons
  • DSI/Sanchez

*Okay and Center both made unstamped magazines as well as the stamped variety.

These are all considered roughly equal except for Colt, which is more of a brand-image thing. Since they never made their own mags, they're not really a manufacturer technically, just a baseplate (same for Bushmaster prebans). Cooper had a bad run where their welds failed, but I inspect every magazine before I advertise it (hopefully, before I buy it), regardless of the name on the baseplate: welds are definitely something I look at. DSI Sanchez also caught a bad rep for FTFs, but I think their problems were mostly follower-related and were cleared up with the introduction of green followers.

Of this unmarked tier, I actually prefer Labelle and Parsons, as they seem to "wear" the best. Parsons mags in particular age quite well.

Price should depend on condition, but sometimes condition isn't the primary determining factor. For example, date-stamping will override condition in many cases. I sell a lot of Okay mags that are "in the gold," just because they are date stamped. It's a strange market with its own idiosyncrasies.

Mag body color/remaining finish isn't the biggest factor for me. Actually, it's one of the least important factors in my evaluation scale. Far more important are things like: dents in the mag body that will prevent follower travel (fatal), weld failure, spreading feedlips, or feedlips that are worn thin (most common issue), missing baseplate tabs (not fatal, but not attractive either), and broken baseplates (must be repaired or replaced before sale).

Feedlip condition can be really tricky and as far as I know, nobody explicitly inspects mags like I do. You have to look at the magazine straight on and see if the front of the feedlip section is sharp or not. Sharp means a lot of rounds have passed through the lips and the aluminum's been worn away from underneath: such a magazine is going to have less life left in it. All feedlips will be radiused slightly on the inside, but if it looks like you'll get a cut from passing your finger over the follower and between the feedlips, that's a bad sign.

When I come across a magazine that I don't have confidence in selling at full price, I'll usually give it away in a Karma, with full disclosure as to why.

Colt "62667" Magazines:

There is a special class of 30 round magazine that I haven't mentioned prior and that's the Colt "62667" magazines. These are the earliest straight/curved 30 rounders and were made for a contract run (thus were not mass-produced or marketed directly to the public). They shipped with Colt baseplates and are stamped "62667" on the body. They also came with dark green followers with "62665A" painted on in white lettering. These are the closest you will get to a stamped preban Colt magazine. They are valued because of their rarity and collectibility, though I suppose you could replace the 62665A follower with an MP follower and have a reasonably functional verifiable preban magazine.

Colt Body

Colt 62677 body inscription

The magazine above has obviously seen some miles. A 62667 magazine in new condition looks like any other preban era grey USGI magazine, except it has "62667" engraved on the body (and the green follower w/ white lettering, which we'll get to later). You can still see some of the original finish in the valleys and lettering of this magazine. Actually, the wear on the highpoints makes the lettering more obvious for us, beneficial in this educational & identification sense.

Colt Follower

Unique Follower

If the follower looks slightly forest green to you, it should. This is somewhat of a bad example for the lettering as the white markings have worn down some, but the follower is marked "62665A."

Colt Floorplate


Not necessarily unique to this series of magazine, but included for reference.

This particular breed of magazine is sought after not only by those in preban states looking for verifiable preban magazines, but also by Colt collectors nationwide, and those looking to complete "retro" style AR builds.

Preban Magazine Prices:

Historically, my sell prices (dependent on volume, condition, market pricing, etc) have been (roughly):

  • CI & ID mags: $16-18
  • USGI Teflon: $19-21
  • Ext Date Stamped USGI: $16-19
  • Int Date Stamped USGI: $15-18
  • No Date Stamp USGI: $12-15
    [Past figures are not an indicator of future performance]

The above prices generally reflect the installation of a Magpul follower in the magazine (though, historically, some of my early and volume sales did not include MP followers, cuz I was too poor to have them on-hand).

The above is not an indicator of average market pricing, just what I've been able to sell mags for.