Is the M16 built by Colt - the player's choice

 An overview of the AR 15 family of weapons

After a lot of back and forth, I decided to create an almost complete guide around the AR15 family of weapons.
Over time, the whole thing has degenerated quite a bit due to the fact that, along with the AK system, it is one of the most extensive weapon families in the world.
The guide is divided into the following sub-items:

1. AR15 model overview
2. Current special versions
3. Receiver overview
4. The SOPMOD kit
5. AR15 stuff

The whole thing should help with orientation in the Colt designation jungle (sooner or later everyone desperately;)).

AR15 model overview
First of all, you should be aware that the AR15 system is based on the AR10. But I did not list this one because it did not belong to this weapon family, but was a completely independent prototype from Stoner.


But you can already see the close relationship to the M16 in the locking system. The trigger-like loading lever is also reminiscent of the two-sided operation of the M16-typical T-lever, it was to be picked up again decades later by other developers (FAMAS).

In addition to the fire modes, one of the main or classification criteria is the upper receiver used (see below). But here and there it happened that Colt gradually updated various weapons based on the M16A1 with M16A2 receivers, without mentioning this in the product catalog. This makes classification and identification very difficult.

On the subject of export models: The term "export version" logically does not necessarily make it clear that these weapons are only intended for overseas. Many versions were also sold to authorities, etc. Here, too, it was said "the demand controls the supply", which is why these versions were most likely available in very different quantities or with M16A1, M16A2, M4A1 receivers. As with all export versions, Colt has unfortunately never (or only very incompletely) documented such changes, which leads to many misunderstandings.

Unless otherwise stated (see the attention on the M645), all weapons have the semi-automatic and full-automatic fire modes. With some models, however, it could (and was) often confused, ie. I clearly wrote it again for these. The table-like system is completely structured:

ColtNo - old. Designation (optional); Description; Run length (opt.); Year of development (opt.)




  • M603K - M16A1; produced for Korea, identical to M603 but special serial number (K0000000); 1967
  • M604 - M16; produces for Air Force without Fwd. Assist; 1962
    Attention: It is not known whether the M604 is based on the M16 or the M16A1 in terms of system technology, but the markings contain M16, which is why the old one. Name and year of development.


  • M605A - M16 Carbine / CAR-15; Carbine version of the M16A1 with solid buttstock; 15 "
    Warning: It is not known exactly what this model looked like. However, I did find a picture that can document this model. However, this is equipped with an XM177 type Foregrip, which doubts the authenticity of the M605, it might be more possible that it is an M651. In addition, all of the following short and carbine versions (except for all M4 versions or XM177 versions) can be referred to as CAR-15. This is of course not wrong, but it is also confusing. Unless otherwise stated, all carbine versions do not have a bayonet lug.
  • M605B - ​​M16 carbine; identical to the M605A but without Fwd Assist and with 3rds Burst
    Attention: It is also unknown whether an XM177 type Foregrip was also used with this model.

  • M606 - HBAR Assault Rifle
  • M606A - HBAR Assault Rifle with Fwd. Assist
  • M606B - HBAR Assault Rifle with Fwd. Assist and 3rdBurst
    Attention: It is not known for all M606 versions whether they are based on M16 or M16A1.
  • M607 - is based on M16 in terms of system technology, but already with Fwd. Assist, reduced M16 foregrip, and lockable sliding stick by Robert E. Roy and XM177Type flashhider; 10 "; 1965
    Attention: This cute looking model was completely developed for Colt by Robert E. Roy and was the decisive factor for the XM177 and the introduction of the foward assist. It was also often incorrectly called SubMachineGun (SMG), not to be confused with the other smaller 9mm variants.
  • M608 - CAR15 "Survival Rifle"; With "fixed tubular buttstock", shortened grip and simple cylindrical foregrip; 10 "; 1965
    Attention: This model is another exotic model that was probably developed parallel to the M607 and is therefore dimensionally identical to it. It was developed by Roy as a for the Air Force along with a few other prototypes, presumably as a back-up weapon for flight crews to replace the old .38 Rovolver. Only 10 of this specimen were built.



  • M609 - XM177E1; Carbine based on M16A1 with a new type of foregrip and sliding stick for the Army; 10 "; 1967 or 68

  • M610 - XM177E1; identical to M609, product for the Air Force ie. other markings; 10 "; 1967 or 68
  • M610B - XM177E1; identical to M610 but with 3rds burst (also for AF); 10 "
  • M611 - identical to M606 but export model ie. other markings
  • M611P - identical to M606 but with extra markings as an export version for the Philippines ("Made by Elisco Tool for the Republic of The Phillipines")
  • M613 - Export version of the M603 ie. other markings
  • M614 - identical to M604 (M16A1 without Fwd. Assist) as an export model with different markings
  • M614S - M614 licensed from Singapore, other markings
  • M616 - Another export version of the HBar M606 with again different markings
  • M619 - Export version of the M609, different markings
  • M620 - Export version of the M610, different markings
  • M621 - identical to M603 but with Heavy Barrel (HBAR)
  • M629 - XM177E2; identical to M609 but with a slightly longer barrel and flashhider; 11.5 "

  • M630 - identical to M609 but without Fwd. Assist developed for the USAF; 11.5 "
  • M633 - RO633; a "thoroughbred" SMG in 9mm, based on M16A1 with numerous changes in technology and appearance (Foregrip), with Case Deflector and XM177Type Sliding Stock as well as with "Mechanical Buffer"; 178mm
    Warning: I don't have what the "buffer" is, but it is probably part of the modified closure.
  • M633HB - RO633; identical to M633 but with "Hydraulic Buffer"
    Attention: As you can imagine, the abbreviation HB does not stand for Heavy Barrel but for "Hydraulic Buffer".

  • M634 - identical to M633HB but with a longer barrel; 10.5 "
  • M635 - RO635; 9mm SMG based on XM177 with technical modifications like M633, without Fwd. Assist; 10.5 "


  • M639 - XM177E2; Export version of the M629, different markings; 11.5 "
  • M640 - XM177E2; Export version of the M629 but without Fwd. Assist, other markings; 11.5 "
  • M645 - M16A2; Basically M16A1 based, but with profound changes and adjustments: Modified receiver with new side adjustment and added height adjustment for the rear sight in the carrying handle, exchange of the FA mode for a 3rd burst limiter (which should prevent ammunition consumption through unrestricted continuous fire), improved Fwd . Assist, new barrel with adaptation to the improved M855 cartridge standardized by NATO as SS109, new bayonet nose and a new foregrip (based on the XM177). Better plastic materials were used for both the Buttstock and Forergrip and the Pistol Grip; 20 "; 1983
    Attention: Even though a 600 catalog number was used for the M16A2 (due to its descent from the M16A1), Colt probably did not know what kind of wave it had triggered. Many of the carbine versions that have already been released for the M16A1 should now also be designed for the M16A2, which is why all versions that are basically derived from the M16A2 are designated with a 700 number. Furthermore, unless otherwise specified, all weapons based on the M16A2 are equipped with a bayonet nose and a new barrel profile for the M855 cartridge. Unless otherwise stated, all weapons based on the M16A2 have a 3rds burst limiter.

  • M645E - M16A2 Enhanced; technically identical to the M645, but with a modified upper receiver with removable Carriyng handle on a low profile Picatinny M1913 (Weaver -) - rail and flip up front sight; 508mm
    Attention: This is probably a kind of prototype on the basis of which the M16A3 was developed.
  • M649 - "Submachine gun. For US Air Force, with 14" (356 mm) barrel and 1 in 12 "(1 in 305 mm) rifling."
    Warning: I know by far the least about this model, despite a lot of research. Maybe it was just a prototype with a very limited number of pieces. The text is from
  • M651 - M16A1 carbine; Export model, probably with different markings; 14.5 "

  • M652 - M16A1 carbine; identical to M651 but without Fwd. Assist; 14.5 "
    Attention: It is unclear to what extent these models are identical to the M605 versions, whether the barrel length is the same for both, I don't know either.
  • M653 - M16A1 carbine; identical to M651 but with sliding stick; 14.5 "
  • M653P - M16A1 carbine; identical to M653, licensed product of the Philippines with own markings; 14.5 "

  • M654 - M16 carbine; identical to M653, export model without Fwd. Assist; 14.5 "
  • M655 - M16A1 Sniper Rifle; Experimental rifle with "high profile" upper receiver
    Attention: I also know very little about this model, but contrary to the description I have found some pictures, but I assume that it is more of the M651, as they are carbines with a solid buttstock.
  • M656 - M16A1 Sniper Rifle; Experimental rifle with "low profile" upper receiver
    Warning: I have never seen such a model in the designated version, although one should assume here that the people of have a blunder in their table. Even they should know that a low profile M16A1 receiver probably (!) Does not exist.
  • M701 - M16A3; Export version of the M16A2 with FA mode instead of 3rdBurst; 20 "
    Attention: Now we are back to the confusing part of the M16A2, A3 and A4 story. But since several sources say that the M701 is a fully automatic M16A2, but was not used in the Army (would have been illogical) I stick with it.
  • M702 - M16A2; Export model for the United Arab Emirates, fully automatic with M16A1 rear sight, own markings; 20 "
  • M703 - M16A2; Export model for the United Arab Emirates, fully automatic with M16A1 running profile, own markings;
  • M705 - M16A2E3; Export model based on the M645 but in Full Auto instead of 3rds Burst, other markings; 20 "
  • M707 - M16A2; Export model with M16A1 running profile, other markings; 20 "
  • M711 - M16A2; Export model with M16A1 barrel profile and rear sight, other markings; 20 "
  • M715 - C7; Licensed production of the M16A2 from Canada (Diemaco) with M16A1 rear sight, own markings, fully automatic; 20 "
    Attention: These models also often cause confusion, because several other versions similar to M4A1, M16A2E / M16A4 were also made of these without having been documented by Colt. These weapons are used by various other countries. It is also said that they are qualitatively better processed in some cases.

  • M719 - M16A2; identical to M715 but Colt-manufactured with 3rds Burst Limiter.
  • M720 - M16A2 carbine; Carbine version of the M16A2 with updated sliding stick; 14.5 ";
    Warning: This weapon is in all likelihood the weapon used by the "Deltas" in the movie Blackhawk Down.

  • M723 - M16A2 carbine; Produced for the US Army (Delta Force) and the United Arab Emirates, with M16A1 rear sight and FA mode instead of Burst; 370mm; (late) 80s
  • M725 - C8; Canadian license production of the M720 from Diemaco with M16A1 rear sight and FA-Mode
  • M725A -M16A2 carbine; identical to M725, export version from Colt for the United Arab Emirates with M16A1 barrel profile
  • M725B - M16A2 carbine; Export version of Colt's M725
  • M727 - M4 carbine; identical to M720 but fully automatic, produced for the Navy (SEALS) and others; 14.5 "

  • M733 - M16A2 Commando; fully automatic carbine based on M16A2 with a very short barrel; 11.5 "
  • M733A - M16A2 Commando; identical to M733 but with M16A1 rear sight; 11.5 "

  • M735 - M16A2 Commando; identical to M733 but with 3rdBurst; 11.5 "
  • M737 - M16A2 HBAR; identical to M16A2 but with heavy barrel and M16A1 rear sight
  • M741 - M16A2 HBAR; identical to the M16A2 but with a heavy barrel barrel
    Attention: It is not clear what distinguishes the version from the M16A2 basic model, as this also already has an HBAR.
  • M750 - M16A2 SAW; Squad Automtic Weapon with bipod and FA mode; 20 "
    Warning: DocS pointed out to me that this weapon would also have a handguard similar to M249.
  • M901 - M16A4; identical to M16A2 but with flat-top upper receiver and FA mode; 20 "

  • M905 - M16A4; identical to M901 but with 3rds burst; 20 "
  • M925 - C8FT; identical to the M725 but with a flat-top upper receiver and 3rdBurst from Diemaco
  • M927 - M4A1 carbine; identical to M727, but with flat-top upper receiver; 14.5 ", 1994

  • M933 - identical to M733 but with Flat Top Upper Receiver, 11.5 "
  • M941 - M16A4 HBAR; identical to M741 but with flat-top upper receiver, fully automatic; 20 "
    Attention: I have to refer back to the HBAR story ....

  • M942 - M16A4 SAW; identical to M741 but with flat-top upper receiver, only full-capacity table
    Attention, since has given the M901 the military designation M16A3, but this cannot be correct, after a long deliberation I renamed it M16A4 and also counted all effective weapons in this category.

    At the end of this story, it remains to be said that there are a number of other so-called "bastardized versions" of the system. Including very short carbines and SMG variants.

    Current special versions
    There are currently some weapons based on the M16 system that have more or less been around for a short time, but which have become very popular or are already being introduced / tested. I will now deal with these systems again in stages and add a micro-level description.

    Special purpose rifle

    This weapon represents a new concept in the Army. It is supposed to be the new base for the so-called Designated Marksman, some of whom still counted on the M14 (Marines and SEALS continue to do this). The SPR was in the final stages of its development in 2001 and was developed by the US Army Marksmanship Unit in collaboration with SOCOM.

    The weapon consists of various components. After September 11th and the beginning of the war in Afghanistan, the first 150 SPRs were sent into action with the Special Forces. With great popularity, the combination of a match trigger from KAC and a match barrel from different manufacturers make the SPR extremely precise.

    Leupold is developing a ZF, limited to 110 pieces, for the SPR.

    The roughest description of the changes: New deduction system from KAC or Accuracy Speaks; Railsystem from ARMS Inc .; ZF from Leupold; Match barrel from Douglas, Krieger or Schneider (18`` = 457mm) and an optional silencer from OPS Inc.

    ZM-Weapons LR-300

    The ZM-Weapons LR-300ML is actually a long way from the Colt-M16 system as we know it. It is offered as a complete weapon and as a conversion kit. The conversion kit allows you to build an LR-300 from every AR15 lower receiver.

    This kit is the best way to explain what the LR-300 actually is and what changes will now lead to the LR-300. The kit consists of a complete upper receiver, bolt carrier, barrel, folding stick, handguard and pistol grip.

    It is best to analyze all components from the "inside".The LR-300 bolt carrier is a shortened AR15 version that allows a folding stick to be mounted (otherwise the bolt has a much wider return into the stick).

    This also moves the Fwd. Assist further forward, which results in a completely new upper receiver. A T-lever is supplied, since this does not differ from the standard AR15's, the original lever used for the corresponding lower receiver can also be installed or exchanged.

    Similar to the M4A1, the receiver is a flat top, which allows all Weaver-compatible aiming aids to be mounted. A vertical foregrip can be mounted in various stages on the foregrip.

    There are two barrel lengths to choose from:
  • the 11.5 "barrel known from the M733
  • a longer 16 "barrel

    A phantom flash hider sits on the barrel and the weapon has a stand-alone rear sight for mounting on the Weaver rail. The stick is a folding stick which makes the weapon extremely compact.

    All in all, the weapon with an 11.5 '' barrel is much more compact than an M4A1, unfortunately ZM-Weapons has decided to mount a RAS system. The weapon would be superior to a SIR-M4A1 or an M4A1 with RIS thanks to the same flexibility. The weapon costs just under $ 2,000 and the kit costs $ 1,600. A standard M4A1 costs the Army around $ 900 (excluding RIS and optics).

    M4A1 CQB with ARMS-SIR system

    Another company that wants to compete with the authorities and the military market in the USA with KAC tactical accessories is A.R.M.S. Inc.

    The so-called Selective Integrated Rail System for the M4A1 Carbine also comes from this company. In contrast to the running-stressful rail interface system, the SIR is mounted on the flat-top receiver thanks to the Weaver bracket. The barrel is thus completely relieved. Every conceivable accessory can now be mounted on the SIR without hesitation.

    The SIR-equipped M4A1 CQB was being tested by the US Navy SEALS and the Marines. Results have understandably not yet been released to the public, but it looks like the SIR is becoming increasingly popular. With the tested object (CQB-Carbine) I'm pretty sure that it could possibly even be introduced under the name M4A3.
    According to DocS, this weapon was also tested with 14 "and 16" barrels.

    Receiver comparison
    Through my research I came up with a very well illustrated comparative study of the various upper receivers. Since many people have problems telling these generation-specific components apart, I simply included the whole thing.

    The SOPMOD kit
    The Special Operations Peculiar Modifications Kit for the M4A1 doesn't really need much explanation anymore. This equipment system for weapons is unique in this form and represents a complete set for really every use and every need. From the red dot over 4x scope to IR and normal lasers everything is available what a modular weapon system needs. Despite the current equipment chaos, one can say that the Army has two SOPMOD kits for every four weapons.
    That is why some components (possibly lasers, for example) are available in a double kit.

    I did a bit of searching for pictures and used them to compile a complete listing of this system.

    AR15 stuff
    While searching for information, pictures etc. on the net, I found some extremely interesting pictures and videos about the AR15 / M16 that I simply cannot leave out;).

    An X-Ray image of an M4A1 system, on which you can distinguish the steel and aluminum parts very well.

    An exploded view of the Bushmaster M16A2.

    And a very interesting wireframe video on the function of the gas pressure and locking system of an M4A1: Download

    Finally, sources, because I am by no means omniscient;).

    For the most part, I have my information for the overview and the receiver comparison from - without this page this guide would be very incomplete.

    I have pictures and information from:

    I would like to give a really big thank you again to DocS, who took the trouble and checked the whole thing for content, spelling and grammatical deficits. He also gave me a number of useful tips that I incorporated.

    Tuesday February 10, 2004