Colt 645- This was the first attempt at an “A2” Model 645 is detailed in SAR Vol 1 No 7.
By Dan Shea
The Colt Models ID Guide has expanded somewhat- we are going to have five parts to the series instead of four. Some of the newer readers may not be aware of what we are doing here- basically trying to bring together the existing information about what M16 models were manufactured at Colt. The purpose is to attempt to give the public a guide to what is “Correct” for each model, and how the development process appeared.
This has been a very interesting study, and more information is coming out every day. SAR plans to wait twelve months, then include a copy of all the information that has come to light in the intervening time.
We have had many requests to carry this series into the AR15 Semi-automatic series of firearms. We have decided to do so. In addition to our upcoming guide on the MAC series of SMG’s, we are going to each of the manufacturers of the AR type rifles, and documenting their factory models in the same manner that you see here. We will try to include the serial number ranges pertinent to the 1994 “Ban” on so called “Assault rifles”, so you can keep a ready ID guide to make sure that your purchases are in compliance. Our first four in this new series will be Bushmaster, Eagle Arms, Armalite, and Knight’s Armament. If there is special information about these firearms that you consider important, please let us know.
We hope you enjoy this fourth part of the Colt ID, as Colt moves into the M16A2 Program. The M16A2 was a product improved version of the A1 model, based on many After Action reports and constant field testing. Sighting was changed, burst mechanisms added, barrel twist was changed, the buttstock lengthened, a brass deflector added, handguards were rounded, and barrel contours changed. The JSSAP program was the catalyst for the adoption of the changes, and many were hotly contested. That is a story for another day…
Colt 750 LMG. Safe or Full Auto only, (Two position selector), 600 rpm. 12.9 lbs (No magazine) Open bolt action, Bipod A2 style sights, A2 upper receiver, Heavy 20” barrel.Colt 750 with C Mag. Recently there has been a lot of interest in the 100 round Beta C-Mag. It is frequently seen installed on the Colt 750 LMG model. SAR covered the C-mag in depth in Vol 1 No 5. This photo is included to help identify this commonly seen combination.
Colt 720, “M4”. The 14.5” barrel has a 1:7 RH twist, and a reconfigured barrel contour for use with the M203 grenade launcher. Collapsible buttstock, A2 sights, brass deflector A2 pistol grip A2 compensator. The original M4 carbine has gone through various evolutionary steps recently. Markings may vary from “M16A2”, “M16A2/M4”, “M4E1”. Variations have flat top uppers, new handguards, Rail Interface Systems. SAR will cover all of these at a later date.
This article first appeared in Small Arms Review V1N8 (May 1998) and was posted online on June 30, 2017
