We're any of the original m4 carbines with a2 uppers or c7 uppers roll marked with "m4" or were they only marked "m16a2 carbine" I can't find much info on the origanl xm4 program.    I know by the time in 1994 or so when the m4a1 carbines were out they were all flat top and marked with current m4a1 markings. Did a roll stamp "xm4" ever exist?

The last weapon I had on active duty was a carbine.

From memory (and after 20 years, I don't really trust that!)  the were roll marked M-16A2.

Uppers were standard A2s.

For some reason I want to say the FCG was Safe/Semi/Auto but again I'm not sure about that. I only fired it once for qualification right before I got out.

Don't know if this helps.

Yes, I had a grey A2 Colt upper with M4 ramps, marked m4 in small letters over the gas tube hole. According to Kevin Dockery's 'Weapons of the Navy Seals' the first M4s were A2 uppers. The M4A1 designation came about as the flat top upper was accepted. There is a LOT of controversy about this, but that A2/M4 upper on an NDS lower, with a fixed stock is still my favorite set up for a practical, all - around carbine. I am working on building a couple similar weapons right now. I wouldn't have broken it up and sold it if I hadn't needed the money at the time.

M4A1 has nothing to do with the carry handle/sights, and is the designation for the full auto M4 variant.

Early M4 program developmental weapons were rollmarked "XM4 Carbine."  Coldblue (IIRC) posted a pic once of one of these weapons from when the Marine Corps was involved in the program, it had the fixed carry handle and A2 sights.

Pre-M4 carbines such as the RO727 (A2 sights) and 723 (A1 sights) were rollmarked "M16A2 Carbine."  These were typically full auto.  The 727s had what became the M4 profle barrel, later 723s did as well.  When the M4 feedramps were standardized, Colt started marking barrel extensions and upper receivers with "4" or "M4" to ensure the right combinations were used, so you'll see 727, 723, nd 733 uppers with the "4" or "M4" mark above the gas tube hole on the front of the carry handle.  

Folks will see 727s and refer to them as M4s or even M4A2s, though that is incorrect.  Even high speed, low drag guys, who couldn't care less about the minutia of details we wank about online.

Like I said, lots of controversy about this. All I know is what I've read. Doesn't mean it's true. Doesn't mean it's not. Sorry I even responded to this post - I can see it going downhill already. I don't have Dockery's book, or I'd give a qoute. Doesn't mean he isn't wrong, but he was very specific. The Abu Dhabi carbines did exist, as do 727's. It seems nomenclature is something that people on this sight love to argue about - which is why I refer to the variant as an A2/M4. It's as good a label as any I guess.

The very few developmental versions were marked "M16A4E1" or "M16A4E2" - dunno if they ever bothered rolling out an XM4 rollmark.

I've always understood the Abu Dhabi carbines were RO727s, and reportedly the source of the stepped barrel we have today; Abu Dhabi wanted A2 carbines, with the A2 profile barrel, but the ability to mount the M203.

Lots of good info to be found here. Start in September 1984.

Without going into too much minute detail, having been the topic of many discussions over the years, my belief from the current research and documentation that I have seen is that:

The RO723/5 (auto/burst designations) and RO727/9 were wholly commercial/export developments, and while used by many of the same units that would eventually acquire the M4A1, the M4 and M4A1 are not direct descendants, so to speak, of the RO723/5 and 727/9, though the projects and their later development would almost certainly have informed one another.

These commercial/export M16A2 Carbines were, appropriately marked "M16A2" in the commercial style.  

The XM4 program was initiated in the 1980s and given the model number designation of RO720.  Several barrel profiles were experimented with before the final decision to use what is now known as the "M4 profile," but the upper receiver type was always the A2 sight version with adjustable target sights and fixed carry handle.  

These photos are the most common XM4 photos, along with this photo of what appears to be an RO720 in the Knight's Collection appear to confirm the property markings:







(fifth from the bottom, under the wire stocked M231)


Important to note from all these photos is the barrel profile, different from current M4's or RO727s.

Also - the KAC rifle clearly has government property marks, but it also has a vinyl acetate coated stock, unlike the fiberlite stock seen in the military photographs.  I do not recall what the Knight's carbine is marked as, however, the model designation appears to be short - too short to be "XM4 CARBINE" or "M4 CARBINE," and too long to be only "XM4" or "M4," it looks like it is an M16A2 lower.  However, it is difficult to determine (and I really should contact Knight's on this, and many other items of interest in their collection that I've wanted to look at...) whether it is a) original to the XM4 program, b) original to the upper, or c) the only rollmark used during the near decade of XM4 development.  

What follows is that the M4 becomes type-classified in 1994.  Now - there has been quite a bit of discussion on this matter, and I now believe that the first production series of the CARBINE, 5.56MM, M4 were in fact RO720 models, and equipped with fixed carry handle upper receivers.  However, I am unsure whether they might have continued to be marked, perhaps as "pre-production series" like the M16A2E3s that were accepted into service, with whatever the XM4 was marked - or if they would have had the "M4 CARBINE" rollmark as it currently is.  

My suspicion, though without any solid evidence, is that they were marked "M4 CARBINE," and therefore, once changed from their original configuration from their fixed carry handle uppers, they would have disappeared into obscurity relatively quickly.  

In the meantime, the M4A1 was type classified not a couple months afterwards, in 1995, with the accessory railed flattop upper receiver, and appears to have been so from first delivery, and classified as the RO921.  

More than likely, it seems, subsequent to the first delivery of RO720s, M4 Carbines were shifted to the RO920 model, which also used the accessory railed receiver.  

On the commercial/export front, the RO727/9 appear to have been updated, and the model numbers RO927 and RO929 were introduced into the Colt catalog.  Seemingly they were identical in description to the RO727 and RO729, though, capitalizing on the adoption of the M4/M4A1, the rollmark, in the commercial style of "M4/M16A2E," resembling, but not conforming to an Ordnance experimental designation.  Once again, it is my suspicion that the RO927 and 929 were used as a "dumping grounds" for obsolete 7xx series parts that were to be discontinued in favor of M4/M4A1 components.  

While visually seeming to be almost identical, and impossible to distinguish, at the time of the M4s adoption, assuming that it was a fixed carry handle receiver, the RO720 and RO727 differed not only in rollmark and FCG but:

- barrel profile, the 7xx series A2 barrel is slightly different than the M4 barrel profile
- barrel extension, once again, the feedramp angle is some 5 degrees steeper in the M4 barrel extension than the 7xx series carbines
- handguards
- receiver extension locking nut, round hole versus "castle" style
- receiver extension, two position versus four position

My belief is that the spare 7xx series parts were used up during RO927/9 production (as well as commercial semi-auto production) and slowly replaced with M4 components as the 7xx series components ran out and were discontinued.  This would explain why they warranted another model number, while being identical in specification to the RO727/9.  

In the meantime, the U.S. military had already purchased a number of RO723s and RO727s COTs before the M4/M4A1 became available.  In the meantime, some units, it would seem, perhaps too low on the list for M4/M4A1 fielding in an expedient fashion meeting with operational demands, continued to purchase RO927/9s COTs to augment and replace both 7xx series carbines and M4/M4A1s.  

Thus, seen from a distance, a carbine being used by a U.S. servicemember with a fixed carry handle and M4 profile barrel could in fact be an RO727, marked "M16A2," an RO927, marked "M4/M16A2E," or an early production M4/RO920, marked "M4 CARBINE."  In the meantime, colloquial description had shifted from the then popular "CAR-15" for any and every carbine variant, to "M4."

So, to answer the OP's original queries:


Probably...

...not

..."maybe?"..."


~Augee

Thanks everyone the knowledge here always seems to surprise me following the lead I was given about member coldblue I was able to find the picture of the roll marks.

Here is the picture taken by coldblue

Well wouldja look at that!  

Awesome, haven't seen those before!

~Augee

From everything I've read on the subject ,  it COULD have been possible for an early xm4 to have a m16a2 upper with feild sights. I say possible as I havnt seen a picture confirming but I also havnt found anything really to the contrary. Now I don't believe there was ever a xm4 with field sights produced and sold to the military, but possible in early trials?. Lots of information pointing to early  xm4 carbines using left over 727 parts to make the initial run( thanks Augee) ( like most things colt there Is a weird transition period where almost anything goes) so I wouldn't be suprised to see a few leftover 723 parts being used as well?( no source) maybe that's why I have seen c7 uppers stamped with a 4 on the front above he threads for the barrel nut. ( ill try to find pictures) possibly COTS acquired?

My quest for information continues on

Picture belongs to member LEG

C7 upper marked with a 4

It seems that the c7 upper was well in production until a few years after the xm4 competition was over and it became the m4.
Not saying it is correct , but I really want to find one like that!

http://media.ca1.uscourts.gov/cgi-bin/getopn.pl?OPINION=06-1696.01A


     In the early 1980s, the military determined that it needed a more compact version of the M16. Colt originally designed the prototype for this new weapon under a 1985 contract with the military in which Colt agreed to build and test forty "XM4 Carbines."  In 1990, the military entered into an agreement with Bushmaster to provide sixty-five carbines "having all the physical and technical characteristics of the M4 Carbine."

What were the design permitters for the original "40" xm4 carbines ?

Have there been any reports of m4 or xm4 lowers being used on 723 orders after 1985?

Augee, quick question. After perusing through some older posts I found 2 posts you made and was wondering if you could tell me more

I did also run into a staff-weenie from the 101st at Bagram who had a late RO723, "CH" marked upper with case deflector, .750 notched barrel marked (C) MP, and with commercial rollmarks that read, ETA* - M4/M16A2E. No photographs of that one, unfortunately.

And Just a "by the way," the rollmark on that RO723 was "M4/M16A2E," commercial rollmarkings, just like this one:


Did the late colt 723 have a c7 upper?  Sorry for picking your brain so much. I'm just genuinely interested in this model for some reason. Do you have any more photos of said two rifles by any chance ?

what year did Colt stop making the 723?


The picture you provided

It probably had a c7 upper, (I dont think there are any "C H" marked A2 uppers, I think that was only on the A1/C7 sighted uppers)

The marking above the gas tube hole can be found on AR6520s as well.  it's just how Colt ID'd uppers meant for carbines with the M4 barrel extension to keep them and the rifle uppers separate.

The marking above the gas tube hole can be found on AR6520s as well.  it's just how Colt ID'd uppers meant for carbines with the M4 barrel extension to keep them and the rifle uppers separate.

Thanks. Now my only remaining question regards the m4/m16a2e colt 723

It's odd there would be a 723 upper in the 101st armory, I don't think they're one of the units that COTS purchased the 723s and 727s back in the 80s (those were all SOCOM units; NSW, Rgr Regt, CAG).    Given that 723s were commercial guns, and every 723 I've seen for sale on the NFA boards and dealer websites had commercial "M16A2 Carbine" roll marks, my guess, is it was a throw togther from someone's armory of a 723 upper from somewhere, and a lower from one of those first batches of M4s that ended up in the unit armory o in dudeman's hands througha crackdeal or handmedown, or whatever.

Some of my former employers' Bushmaster "M4s" ended up in the hands of some SF bubbas in Kandahar at one point a few years ago until our govt rep did and inventory of weapons and someone got it by the short and curlies until the weapons were retrieved.  Strange shit happens.

Thanks to all who have posted info on this thread.

The knowledge that is here continues to astound me.

I could read about this kind of thing all day long.

Found this picture in another thread of the barrel profiles experimented with

The carbine I saw in 2008 had an A2 upper with field sights (i.e. "C7").  It may have in fact been something like an "RO923" rather than an RO723, based on the "M4/M16A2E" marked lower.  

Based on the conversation I had with its "owner," though he was from the 101st, I believe that the carbine was in fact Theater Provided Equipment (TPE).  The soldier himself did not specifically tell me so, he was an E3 or 4, IIRC.  He was a Bagramite REMF, and told me that he had deployed with an M16[A2], and had received the "M4" in theater and switched.  

As such, I don't believe that it was organic to 101.  My guess is that it was TPE, passed down from unit to unit, it being by then 2008, if it were TPE, there's almost no telling how it came to be there, considering the number of changes to units, organizations, and TPE between when I departed in 2008 and returned in 2010.  

If I were to hazard wild conjecture, I'd guess that was probably a COTS purchase early on in the war, a lot of units were given discretionary funds to purchase "whatever they needed" to deploy and some interesting things have appeared, like MP5s for PSD, ect.  Possibly an SF support unit, or perhaps a non-organic support unit that had been attached to them purchased them COTS, as they had not been able to secure enough M4/M4A1s prior to deployment (a lot of BCTs were getting very quickly converted to M4s at the time) and either were scheduled to receive the appropriate weapons during reset or simply had no more use of them back stateside, and left them in theater, and they became TPE, and passed from unit to unit - lot of musket bearers on BAF that probably would have loved to have a carbine, any carbine, it's not as if it was going to go anywhere other than Popeye's and maybe the gym.  Once again, if it was TPE, it's impossible to say how it came to be where it was - a lot of units have been headquartered at Bagram at one time or another.  

~Augee

That's along the lines of what I imagined it's provenance would be.

I kinda went that way on mine:

The M4 carbine with A2 upper just looks right.

I have never heard of the M16A4E1 and M16A4E2 nomenclature.  Do you have any more information on these?  Possible mistaken for the M16A2E1 and M16A2E2?

Yes, I believe I was misremembering the M4/M16A2E rollmark.

Sure does. Looks almost identical to the last long gun I had on active duty a long time ago.

Yes I've seen quite a few of them.  The XM 4 carbines for field testing around 1985.  The factory Government issued M16A2 carbine had the same roll mark as the M16A2 rifle.  They were not marked carbine.  They were all equipped with M-16A1 full auto parts instead of A2 burst.kits. The lowers however were stamped safe, fire,  burst.  These were in use around 1988/89.  

Regards

Here is a picture of an early USAF M4A1 flat top I took in July.  Another JTAC carried it in Afghanistan this year. It was a light gray color so I assumed it was an early flat top model.  My original picture had better resolution and I could make out the marking.

PROPERTY
US GOVT
M4A1 CARBINE
CAL 5.56 MM
W 123456

That top one looks like the first style A2 forging.....

+1  

I've got one 733 upper marked exactly the same way, and another that has no marking other than the 4 above the gas tube hole.

im a little late to the party on this one, but reading that gunzone link..colt had double heat shield handguards for the XM4 in 1986...were these the fat M4 handguards that we know today?? because when the 727 came about they still had the skinny single heat shield ones...

I'm currently working on a M4A1 project:

and with some of the info here, I think I may have to make some changes....
So, not only did the M4 have the flat top and A2 upper, but also the C7 (A1 type) upper?

ive seen that called a 723 on here...723 had both pencil barrel and m4 profile...

Now that's an interesting lower.

To my knowledge only US military M4s and M4A1s have the "W" serial prefix.  I suppose those are now in the commercial 6920 runs?

80% lower custom engraved..

Pretty cool.

To the best of my knowledge (based on Federal and DOD Acquisitions) the carbines Uncle bought before the M4/M4A1 had all kinds of dog-and-pony markings, typically M16A1 Carbine, M16A2 Carbine, and Commando.  There were all kinds of upper and barrel combos.

XM4 began under Marine Corps Program auspices in 1983/4.  



USSOCOM made the first official M4A1 purchases in FY 93/calendar 1994.  The Department of the Army Master Priority List for fielding the M4 (burst) was for the 82nd, 101st, and 10th Mountain Divisions, and for armor crewmen to replace the M3 Grease Gun.



I'm sure an inquiry to Colt could tell you when the weapons were first shipped to the Army at the National Inventory Control Point (where Uncle first puts his hands on them and enters the serial numbers into the DOD small arms master serial number inventory).

M4A1 Serial Number 1 is on display in the lobby of USSOCOM Headquarters in Tampa.

im going through that whole site right now, going to make a PDF of all the M4 related stuff..should be done in a day or 2..im at 2003 right now..

i did find it funny at one point we made an order to FN for ONE M16A4..price was $484ish? less than $500...apparently you can get a M16A4 from FN for anywhere from 399-500, but a M4 from Colt is going to cost you around 900

Correct, not an M4, but an M16A2 Carbine RO723/725 depending on the FCG.

       

<snip>

















 
 

For a lower so marked, your only real choice would be to go with a standard flattop upper receiver.  

The question/debate over whether or not the M4 ever came with a fixed carry handle upper hinges on the RO920 M4 Carbine, not the RO921 M4A1 Carbine, like your lower is marked.  The RO921 used a an accessory railed upper receiver from the get go.

Early variants sometimes mistaken for, or erroneously referred to as "M4s" or "XM4s" were on commercial/export lowers, not property marked "M4A1" lowers.  Most common would be the commercial "M16A2" marking.  

I am not aware of any prototype of the XM4 having ever been built or even conceived of with a field sights upper ("C7", "A1", ect.), though the RO723 series used A2/FS uppers - the XM4 was always intended as a variant of the M16A2 with M16A2 sights, whether fixed to the receiver, or detachable.  

The 80% lower you've got is also a modern forging pattern, not the earlier forging pattern, and the earliest M4s and M4A1s were not marked "COLT DEFENSE," but "COLT'S MFG CO. INC.," as Colt Defense had not yet spun off.  

It's a great lower for a build, though, and I only wish I had the means to mill 80% lowers - braceman would have a lot more of my money!  

~Augee

I like it too!  

The izzies did both 14.5 skinny barrel carbines and 14.5 "M4-step cut" carbines with field sights - but that's in-country mods, not Colt factory models, or even US military variants.

I've got an odd upper assembly that came out of one of the marksmanship shops at Ft. Benning.  The guy that gave it to me worked in the shops and he knew I was deploying to Sadi for the first gulf war and thought I might have "use for it" his words.  I put it on a standard M16 lower while over there but never crossed the line so it never even got fired in theater.  I was told this was some sort of test piece for the M4 carbine project, I'm thinking it was just some spares that were laying around in truth.  The upper is a FN item with out the M4 cuts.  the barrel extension also does not have the M4 Cuts.  Barrel is chrome lined Colt 14.5 inches NATO marked and 1 in 7 twist.  Old style Delta ring and HG cap.  Exterior is a black, looks like Teflon finish.  Interior is grey Solid Dry Film lube (SDF).  Has a tear drop FA.  Front sight tower looks original and never remove.  Just a odd set up and thought I'd share.

http://i631.photobucket.com/albums/uu34/donws2/Trials%20M4%20Upper/IMG_0694_zps3f768a8f.jpg

http://i631.photobucket.com/albums/uu34/donws2/Trials%20M4%20Upper/IMG_0695_zps5b73ed62.jpg

http://i631.photobucket.com/albums/uu34/donws2/Trials%20M4%20Upper/IMG_0696_zps7a846f55.jpg

http://i631.photobucket.com/albums/uu34/donws2/Trials%20M4%20Upper/IMG_0698_zpsfc7bcb8c.jpg

http://i631.photobucket.com/albums/uu34/donws2/Trials%20M4%20Upper/IMG_0699_zps67521154.jpg

http://i631.photobucket.com/albums/uu34/donws2/Trials%20M4%20Upper/IMG_0697_zpsf3da04d1.jpg

Some more pictures same upper.

http://i631.photobucket.com/albums/uu34/donws2/IMG_0701_zpse2d6e7b7.jpg

http://i631.photobucket.com/albums/uu34/donws2/Trials%20M4%20Upper/IMG_0700_zps77d6eba1.jpg

http://i631.photobucket.com/albums/uu34/donws2/IMG_0705_zps1c7938c8.jpg

http://i631.photobucket.com/albums/uu34/donws2/IMG_0703_zpsdc1e5cbc.jpg

http://i631.photobucket.com/albums/uu34/donws2/IMG_0702_zps1b92d5a2.jpg

http://i631.photobucket.com/albums/uu34/donws2/IMG_0704_zps3eee8b6f.jpg

Alright, here is the timeline of the M4, from September 1984 to April 2009.  Also some info related to the M4.  I may have included non-M4 related stuff on accident as it all started to blend together after a while

M4 Timeline

There's a variant I haven't seen mentioned in a long time. M4A1K Aircrew Survival Carbine. I remember some pics of one with a cut down grip and shaved toe on the fiberlite stock.

Thanks for posting that. When I have an afternoon free I will finish reading it. Nice work

Outstanding work!