Other then what is posted on RetroBlackRifle...any info? i mean, was it for sure used in Vietnam? Stupid Q sorry...it says USAF...Air force special forces?

I cant find anything else on it!

Thanks, Ethan

The GAU-5A/A was utilized by Air Force Security Police well into the early 1990s.  It would likely have also been used by elite USAF personnel of various types, parajumpers, etc.  If I remember correctly, someone had a picture of what was pretty conclusively a GAU-5A/A in Vietnam.  Whoever it was who posted that might be able to link to it here.

I'm really sorry the RBR forum went offline, because there was a whole discussion thread on the issue of the model number there there.  Despite it constantly being the model number cited in various books, I am inclined to dispute the 649's very existence based on a wide array of factors.  If it did exist, I would cite the same inconsistencies to question whether or not its what it is said to be.  I am convinced the my opinions and logic are no more or less than whatever "research" went into whoever determined first that the GAU-5A/A was a Colt 649.  RBR's AF carbine guide makes essentially brief note of my contentions, but otherwise sticks with the 649 number.  The listing on the site for carbines has the GAU-5/A designation applied to the 630, which is just wrong.  The 610 was both designated as the XM177 and GAU-5/A.

USAF PJ Vietnam 1970

I carried a GAU-5A as a USAF Security Police K-9 Handler.

I did not know the Air Force had 30's in Vietnam.

Million Dollar question!  Best of luck getting the answer!

If you follow the “rational” of the Colt and US Military Designation system,

Colt Model 609 – US Army XM177E1
Colt Model 610 – US Air Force GAU-5/A

Colt Model 629 – US Army XM177E2
Colt Model 630 – US Air Force GAU-5A/A

However here is where the problem lies,
None of the documentation in Black Rifle I or II mentions or supports the existence of a Colt Model 630 as a 5.56 Carbine. The model chart in Black Rifle II actually lists it a 9mm Carbine.

The model chart in Black Rifle II actually lists the GAU-5A/A as a Colt Model 649.

Chris Bartocci came up with that chart with information provided by Colt.

If you check the various other references out there, you will find a mix of information. Some of them list the existence of the Model 630 as a 5.56mm Carbine, some do not. Some list the GAU-5A/A as a Model 630, others list it as Model 649.

What is the answer, there are a number of possible solutions IMHO,
- Assuming the 630 was a 9mm, Colt did not initially plan to produce a GAU-5A/A, so the next number in line being 630 was given to the 9mm Carbine when it was produced. Then when there was a demand for the GAU-5A/A, the numbering had advanced and it was designated as the 649.

- Assuming the 630 was NOT a 9mm, Colt did initially produce the Model 630 as a GAU-5A/A, but then after an initial production run, a later production run was also done under the Model number 649. This would mean both the Model 630 and 649, were both supplied as the GAU-5A/A.

Unfortunately this late in the game, I am not sure if anyone will ever know the true answer? I am sure the answer exists somewhere buried in the archives of Colt or the USAF, but I am not sure if anyone would ever be able to find it?

I pursed the issue as far as I could with the help of a lot of other folks, but I never could get to the pot of gold at the end of the rainbow. Maybe when I am retired and have nothing better to do with my time I may go back and try to track it down.

Best of Luck,
Capt Richardson

PS: I will check Retro Black Rifle on that Model issue, it may have come up/happened during the recent switch over.

In my opinion its not just a matter of following the rationale, its a matter of following the otherwise consistant logic, no matter how absurd Colt has been over the years and dicking with it.

All the weapons in the CAR-15 family, with the exception of the 608 and 607 (sort of, there was a forward assist equipped subvariant) were produced in pairs with and without forward assist, including the export/commercial variants.  All the other 5.56mm SMG/Carbines were paired up, straight into the the export 11.5" guns.

You had:

609 - 10" SMG w/ forward assist
610 - 10" SMG w/o forward assist

619 - 10" SMG w/ forward assist (export/commercial)
620 - 10" SMG w/o forward assist (export/commercial)

629 - 11.5" Commando w/ forward assist

639 - 11.5" Commando w/ forward assist (export/commercial)
640 - 11.5" Commando w/o forward assist (export/commercial)

Now we know that the 639 number was reused for an export/commercial 9mm SMG type in the 1970s, around the time the 3" muzzle device was declared a silencer and the Carter administration banned the sale of sound suppression equipment abroad.  In my mind there's really no doubt that this led to the development of the 11.5" transitional types, and final A2 types, in the 700 series.  The first batches of 733s from most accounts were essentially 639s with the A2 flash hiders and grips and some pretensions to being "A2" standard.  Some of these probably existed with birdcage flash hiders making them even closer in actual spec.  I can see the 630 being reused or being planned to be reused as well around the same time, seeing as the entire 630 series became a holding tank for 9mm weapons, which only appeared in the late 1970s and early 1980s IIRC.  That a decision was made to start with 633 to match up with the 733 is something I can easily see as well.

I can also see the USAF requiring replacement weapons and parts for their decidedly old GAU-5A/A weapons by the 1980s.  That Colt might have assigned a new model number, 649, to account for this, could easily have happened.  With the exception of the 640, which is clearly paired up with the 639 and dates back to the very late 1960s from what I can tell, the rest of the 640 series are rifles dating back to the early-mid-1970s.  Since the 650 series is full of weapons dating back to the specialist weapons dating back to the late 1960s and early 1970s, it seems decidedly odd that circa 1967, that Colt would have tossed the weapon into the 640 series out of sequence instead of putting it into the 650 series, like it decided to do with the 655/656.  This is especially odd when you consider that the 640 appeared either at the same time or later, was of the identical configuration, and was intended to be an export/commercial model, at least from what I can tell.

I honestly think I might be on to something with this theory about 9mm weapons reusing numbers in the 630 series.  I would fit with a known instance and lead to Bartocci putting it in the list as a 9mm variant.  Not one of the many cited works I have on this are consistent either, leading me to determine that this has been a source of confusion for everyone who has tried to investigate it.

hm...So, what in theory is....the 649 was not an original carbine used in vietnam? it was an export model sent to other countries? or? yea im confused...Sorry for my ignorance......I just want to build a carbine that was used in vietnam... is there no proof of this particualr carbine being used in vietnam? on RBR i see pics of it in the 80's and all...

Again any thanks for all your replies!

Ethan

If you're looking to build a carbine that was used in Vietnam, then it is simple without getting into the specific Colt model numbers, which is what is being discussed right now.  

Your lower options are partial fence (XM) or full fence (A1)

Your barrel length options are 10" or 11.5"

You can FA or no FA

You will probably need a moderator of 3.5" or 4.5" length

A1 style sights

Your stocks are any of the first three carbine varieties, shortened A1 (607), anodized aluminium, or vinyl acetate coated, all in the two position variety.  Do you want something that's dead to nuts period accurate, or representative?  

HTH,
~Augee

well... its between the XM177E2 look...and the 649 or 630 Look.... either of these bc they are 16" in length im kinda fond of the non forward assist look...but at the same time whatever i build i want it to represent a particualr type of carbine..not model number..that was used in vietnam... hope that makes sense ha the E2 seems like it was used more extensivly with special forces and all.. i can find a similar carbine that was used but w/o forward assitst...that has the same barrel which is what im using

I believe the 649 was used at Son Tay.

An 11.5" carbine w/o forward assist was definitely used during the Son Tay Raid.  The model numbering, or military nomenclature, is unknown.

Check out the carbine variation guide tacked at the top of the forum.

Here's a basic list of parts for a Vietnam era Carbine/XM177E2/GAU clone.

NDS-604 Upper (I think you mentioned non-FA)
NDS-XM16E1 or NDS-A1 lower  your choice
11.5"  lightweight barrel from JT Dist. or your favorite vendor.
5.5" slip-over moderator to make it legal.   Must be perm. attached.
Set of round Colt 6-hole handguards
Round flat or delta slip ring
Colt 2 position vinyl covered stock or one from Essential Arms.   Both will be hard to find, pricey, but around.
A1 grip
A1 Port Door

Those are the major cosmetic parts.  All other parts are basically any generic AR15 parts without getting to anal about exact period details, etc.  
Most of us retro junkies are pretty anal about details, colors, variations, etc.  But the above list is the basic legal generic Nam clone.