Am excluding the GUU series, while largely made of Colt parts they are not a factory item. Will add the MK18 MOD 0 later on.
USGI GX5857 Colt Model 607, these carbine are US PROP marked found in the 14,500-14,916 serial number range, and roll marked GX5857. These were made up as part of the 1965 S.A.W.S. contract (photo by Tokoi):
USGI M177E1/CAR-15/Commando, these carbine are US PROP marked found in the 900,000-909,999 serial number range, and roll marked COMMANDO. First deliveries occured in Nov of 1966, and issue in Vietnam was completed by March of 1967:
US Air Force GAU-5/A/CAR-15/Commando, these carbine are US PROP marked found in the 900,000-909,999 serial number range, and roll marked GAU-5/A. First deliveries occured in Nov of 1966, and production was completed by the Spring of 1967:
USGI XM177E2, commonly referred to as a “CAR-15” or “Commando” 1967-1970, these carbine are US PROP marked found in the 900,000-909,999 serial number range, and roll marked XM177E2. After US military production ceased in 1970 Colt continued to manufacture an export version of this Carbine as the Model 639:
US Air Force GAU-5/A/A, commonly referred to as a “CAR-15” or “Commando” 1967-1970, these carbine are US PROP marked found in the 900,000-909,999 serial number range, and roll marked GAU-5/A/A. GAU-5/A/A Carbines, or an export version with SINGLEPOINT optics were used in the Son Tay raid:
Commonly referred to as a M16A1 Carbine, slang as "CAR-15", nine million serial number range, 1971-1984?:
Commonly referred to as a M16A2 Carbine, slang as "CAR-15", 8 million serial number range, 1984-?:
723 with A2 profile barrel and M203 cut
Commonly referred to as a M16A2 Carbine, slang as "CAR-15" or "M4", 8 million serial number range, 1987-?:
Commonly referred to as a M16A2 Carbine, slang as a "CAR-15" or "M4", 8 million serial number range, 1988-1993:
Commonly referred to as a "Commando", 8 million serial number range 1984-1993?:
USGI M4 Carbine, W serial number prefix, US PROP marked, 1994-current:
USGI M4A1 Carbine, W serial number prefix, US PROP marked, 1994-current:
USGI M4A1 Carbine with heavy barrel, W prefix serial number, US PROP marked, deliveries beginning as early as January of 2001, to current:
Commonly referred to as a “Commando”, A serial number prefix 1992-current (might pull this one, not sure they were ever issued):
Keep in mind that Colt used up quite a supply of 600 series parts on early 700 series Carbines. For example, just because a 723 should have a delta handguard ring don't mean that it will, because quite a few were sent out from the factory with the older slip ring.
3.5” 607 moderator (photo by Ordnance):
4.5” moderator used on the 607/GAU-5/A/GAU-5/A/A/XM177E1/E2 (Total Silence reproduction):
When the “grenade ring” is installed correctly it covers the lock washer (GAU-5/A/A and XM177E2 only):
Bird cage flash suppressor used on the 653:
A2 flash suppressor used on the 700 and 900 series:
Early lock washer on left, as used on the 600 series. Middle is the A2 peel washers used to time the A2 flash suppressor to TDC on the 700 series, and early M4/A1’s. Right is the current crush washer used on the M4/A1 starting in 2000:
M VP marking found on the 607 (photo by Ordnance):
GAU-5/A/XM177E1 barrel marked MP on right side of the barrel (photo by ranchhand):
We only have one GAU-5/A/XM177E1 example and it has the following numbers stamped on it (photos by ranchhand):
GAU-5/A/A/XM177E2 barrel marked C MP C. C meaning Colt, M meaning Magnetic particle inspected, P standing for Proofed, and the C marking indicates a chrome chamber.
Early 653 barrels were marked C MP B, the B meaning chrome Bore, and they were 1/12.:
Starting in 1974 653 chrome bores were marked C MP CHROME BORE. This marking was also used on early 1/7 twist 723's barrels:
Early on 723 barrel markings were changed from that used on the prior 653. The C MP marking means the same as before. The NATO 1/7 specifies the rifle is designed for NATO standard ammo rather then M193 as used with the 653:
733 barrel markings, the CB meaning Chrome Bore:
727 barrels have the same codes as M16A2 barrels, but are in two rows, and the C is in parenthesis (Note that some 723's use this same marking):
M4/A1 barrels are marked similar to 727 barrels:
Starting as early as 1989 a single or two digit code by the front sight base is used, this one marked 56. Not sure of the meaning, maybe a lot code?
Early 727 barrels, as in 1988 had a star stamped near the chamber, meaning unkown:
As early as 1989 an O is stamped by the chamber (some look like C’s) were the star was previously, indicating a chromed chamber/bore:
Starting in 95 a date code is stamped by the front sight base all though barrels can be found with dates as early as 02/95 production continued well into 1995 with some barrels being dated and other not. First two digits is the month, second two digit number is the year, this one 03/02:
This one 11/00:
Beginning in the late 90’s a paint mark is added in front and under the barrel nut, not sure of it’s meaning (note that the barrel nut is improperly installed, seen quite a few like this since 1998, they don't work very well):
Original front sight base forging was machined to remove forging flash:
From 1971 on front sight forging was no longer machined to remove flash:
Original front sight base had no forge code:
The .625" "C and Bell" front sight base was used on Colt Carbines from 1971 until the late 1980's (653 pictured):
Late 1980’s “C and Bell” FSB on a 727:
"Crown" front sight base was used on some 700 series Colt Carbines in the Mid 1980's, this one on a early 723 barrel (photo by YardDogOne):
“BFI” in diamond FSB are commonly found on mid to late 1980’s Carbines:
Front sight bases coded with a letter the a R1 in circle and number were common in the late 1980’s onto the mid 1990’s:
Typical gibberish front sight forge code, such codes have been used since the late 1980's:
The M4/A1 front sight base is similar to earlier front sight bases, except that the platform the sight post screws into is higher, these are marked with an F on the left side, and use a standard A2 front sight post. The "F" front sight base went into production in 1995. At least one large 1995 batch of flat top M4A1 Carbines were issued that did not have F front sight bases and used standard A2 front sight post.
607 front cap was the same as used on rifles:
Standard handguard cap:
Handguard cap with M203 clearance cuts. Pictured is a early variation on a 727:
Regular production handguard cap with M203 clearance cuts. These were used on later 723 Carbines, and on the 727 and M4 series.
Original front pivot pin lug was black counter bored:
Starting in 1970 front pivot pin lugs were gray and not counter bored:
GAU-5/A/GAU-5/A/A non-forward assist upper did not have a forge code:
Forward assist upper used on the 607/XM177E1/E2 did not have a forge code:
Forward assist upper used on the 653 typically had a CH forge code:
The 723 and 733 upper incorporated a cartridge deflector:
727 upper was the same as used on the M16A2 with the addition of extended feeding ramps:
M4/A1 Carbine and the 933 ( 920/921/921HB/933) utilize a flat top upper:
Soon after working on carbine versions of the M16A2 Colt found that M855 fed low due to various reasons. To maintain reliable feeding the feeding ramps in the barrel extension were lowered into the upper receiver.
Left, M4 feed ramp used on the M4/M4A1.
Middle, extended 700 series Carbine feed ramps. These are shallower then the feed ramps used on the M4/M4A1, date app 1988-1992, are commonly found on 727 and 733 Carbines/Commandos, some later ones are even stamped "4".
Right, standard rifle feed ramps. These feed ramps were used on 600 series Carbines, and can be found on 700 series Carbines as late as 1990:
Extended 700 series Carbine feed ramps cut into upper:
M4/A1 feed ramps cut into receiver:
Extended 700 series Carbine feed ramps, note the chrome on the inside of this 1988 727 barrel extension:
M4/A1 feed ramps, note extension marked “4”
GAU-5/A/GAU-5/A/A /607/XM177E1/E2 front swivel was attached via a roll pin:
1970 and on Colt Carbines had riveted front swivels (save the M4/A1):
Early M4/A1 swivel was a pinned on type developed for use with the M16 series and the M203. It was reversible so it could be used on both .625" and .750" barrels:
Late M4/A1 swivel, same as before but now .750" only, used in 2000 and on production:
GAU-5/A /607/653/XM177E1 used a standard slip ring:
The GAU-5/A/A/XM177E2 , Colt 700 series, and later used a tapered delta ring:
Top barrel is standard profile as used on the M4 and early M4A1. Lower barrel is the 4 oz heavier barrel used on M4A1's, or Colt Model 921HB as early as January of 2001:
The forward M203 cut out on 700 series Carbine and the M4/A1 are a bit different. The angle slopping into the cut out is sharper 700 series Carbines. Model 727 on top, and M4/A1 on bottom:
607 handguards, note the rear handguard cap (photo by Ordnance):
Handguards, 600 and 700 series on left (excluding the 607), early M4/A1 in the middle, and late M4/A1 on the right. Early M4/A1 handguards are double heat shield, and late (1999 on) M4/A1 handguards have glued in double heatshields and are more matte.
Front sight post used on the 600 series Carbines was the same as that used on the M16A1 except it is about .040" taller:
Front sight post used on 700 series Carbines are the same as that used on the M16A2, save it is about .040" taller:
Front sight post used on the M4/A1 is that same as that used on the M16A2:
600 and 700 series Colt Carbine buffer on the left. On the right the "H" buffer used on the M4/A1 (note the flats on the sides of the "H" buffer). There are more variations of the buffers, will add them once I get ahold of some examples:
The "H" buffer's pad is pinned on. Early 600 series also had a pinned on pad (not pictured):
600 and 700 series Colt Carbine 2 position receiver extension on bottom, M4/A1 four position receiver extension at top:
600 and 700 series Colt Carbine castle nut on left, M4/A1 castle nut on right:
607 buttstock (photos by unkown)
607 buttstock details (photos by Ordnance):
Top GAU-5/A/XM177E1 buttstock, it is the same as the bottom standard 600 series aluminum Colt buttstock, but lacked the coating (photo by Ordnance):
Top, standard 600 series aluminum Colt Carbine buttstock, used from about 1967 until the mid 1980's.
Middle, buttstock used from the mid 1980's up through 2002.
Bottom, modern Colt buttstock used since 2002:
Typical Colt aluminum raised markings (photo by Ordnance):
Buttstock pictured in the middle are typically marked with a raised "N":
Sure, a tack would be fine. Did not get to finish it up last night, decided to post what I had done. So expect a major edit on the text.............
I've never built an AR before, so I am confused about one thing. How can you tell the barrel nut is installed improperly on the camo'd carbine in the pics above?
Ekie, Again, I am impressed with what you do here. Great info that really helps set this forum apart.
These threads are the best. Great stuff Ekie.
Wouldn't you love spending a few hours with one of the old salts down at the Hartford plant? Surely they have a showroom, or quasi-museum.............right?
The 733 is still being produced, in its current iteration with the 4th gen "enhanced" stock and A2 rear sights. From what I've seen it, like other early 700 series had a number of transitional variations. We've talked about this, so are these just what you're considering the "standard" configurations?
Ah, alright, missed that, sorry.
Does anyone know if mottled furnature (pistolgrip/handguards) was ever found on XM177E2s?