For some inexplicable reason, I've gotten it into my head to refurbish my current "BHD" style RO727 clone to a more proper RO727.  As always with RBRD, this involves lots of searching and lots of money which I don't have.  

In particular, this one has caught my eye:



Of course, I've got basically no way to justify building a clone of this carbine, it's obviously a DMR-type rifle, and I'm sure it did it's job perfectly well at the time, but nowadays, there's about a thousand better ways to build a rifle for that job.  

Nevertheless, can anyone identify what scope that may be mounted up there?  Also, the carry handle scope mount looks considerably longer than what's normally available.  Any ideas on where I can find one that long?  

I'm still not sure that I will build that exact configuration, I've managed to get my hands on an Aimpoint 1000 as well, and I may just leave that on there, but for some reason the painted Harris 9"-13" and wacky, jerry-rigged cheekpiece intrigue me.  I do want to know where I can source the proper items, though, or ones similar enough for a "spirit of" build.  

I'm thinking that I may have to buy an "in the white" NDS A1 lower, and have it engraved as an SBR and anodized preban grey, and get my hands on an actual Colt RO727 upper, instead of the black A2 rifle upper and CMMG 14.7" barrel I've currently got up there.  Looking at the period photos, it looks like most of the 727s that the Army got have been built on A1 forgings, not A2.  Meaning I'd have to get another Colt two position RET and lock nut... Form 1 for the tax man...

Jeeze...

More current pics, with Aimpoint 1000!










~Augee

Kind of a loose tag...

I'm still a little in the dark (ha!) about BHD-ish period Surefires.
I currently have a 6P on mine and was told this was correct - so when was the "Classic Era"?

'cause I have one of those, too.

I've been running into a little confusion about that too,

When I first started, I went simple, and just used a Surefire Classic, like in the movie, it seemed "close enough," and in the "spirit of."  However more research into period photos made it clear that they were not using Classic series lights, but I couldn't at first identify them from the tiny, grainy pictures, so I simply stuck with the Classic for the time being.  No one else seemed to know or care .  727's are kind of black sheep here on the retro forum, they're grudgingly allowed to be discussed, even though they have barrels of .750 diameter, notch cut for M203s, no less, A2 sights, and 1/7 barrels, a trifecta that might usually get you sent packing from the retro forum, but the interest in retro optics and accessories have saved us, as well as interest in the BHD era as an historical event, and not a current event.  

Anyways, once you posted your thread, which I responded to hastily, saying that the Classic was incorrect, and another user claimed that the 6P was in use at the time, I went back to my reference pics, and determine that there was in fact a very high likelihood that the lights in use in the photos were in fact SF 6Ps.  So, I went back and swapped out my Classic for my beat up 6P (pre-distressed ) that I used to have on my duty carbine, which already had the Weaver mount on it and everything, one for one drop in replacement.  

~Augee

I've been interested in the actual weapons used by our side in the Mog too. It's my understanding that the Rangers swapped out the burst fire A2 lowers on their 727s for the older 653 A1 lowers they already had for the full auto capability.

I can see them doing that with their 720/XM4s, but the 727 is already full auto, and IIRC only comes into existence around 1994.  The 720/XM4 and 723 are the weapons I hear most often quoted for US forces in Somalia.

EDIT- Okay, I the wrong, but I still don't think anyone but the USN ever issued the 727.  They were supposedly first issued to the SEALs in 1988.  The USN currently says its the only operator of the system, but I'm not sure whether that's an "only one ever" or just currently comment.

I still stick by my comments about the 720 and 723.  The annoying thing in both of these cases were the number of modifications and parts combination of weapons in the field.  I know there were 723s refitted with the M4 barrel, giving the appearance of the 727, but definitely being known to be 723s.  Ekie has one of these uppers in the carbine guide.  The 720 upper should be the same as the 727 upper.  The only thing different would be the lower (S-1-F v S-1-3).  If the lower was replaced with a 653 lower then it would be an A1 type.

RO720 had a different barrel profile than both the RO723 and RO727.  

AFAIK, the RO720 was never an issued weapon, just a prototype that eventually developed into the RO920 - M4 Carbine, and only ever used for testing and for trials.  

The 723 and 727 were commercial/export models, sometimes known as the "Abu Dhabi Carbine," Colt's nomeclature for both was simply "M16A2 Carbine."  Both the 723 and 727 were purchased by USSOCOM as COTS items, without any TDP, while the RO720/XM-4 project was the subject of heavy trials and testing.  

The RO723 was originally available with the .625 lightweight barrel with a 1/7 twist, while the RO727 introduced the .750 barrel with M203 notches, that was fitted to the RO723, as well, and marked (C) MP 1/7, rather than the C MP 1/7 marked barrels that current M4s use.  

You're correct that it seems that the Army tended to use more RO723s than 727s.  The Navy was the primary purchaser of the RO727, and still uses them, however, they were also used by the 75th Ranger Regiment, and are well documented in photographs, especially from Gothic Serpent.  As recently as last year, I've also seen RO723s in Army service in Afghanistan, as well, on an A1 forging.  

As far as the lowers go, as commercial/export models, they could be supplied with either S-1-F or S-1-3 FCGs.  IIRC, most were bought with S-1-F FCGs for both Army and Navy service.  During that time, production of the M16A1 had been wound down, and Colt was transitioning into the production of M16A2 variants.  Because of the TDP, all M16A2s sent to the military were required to be delivered with A2 lower forgings.  Commercial and export models, however were quite often built on leftover A1 style lower forgings, including many RO723s and RO727s, even while being marked M16A2.  

While its possible that some RO727 and RO723 uppers were retrofitted to RO653 lowers, I'm guessing that the majority of the 727s in use by the Rangers during Gothic Serpent were factory 727s built on A1 lower forgings.  

     

RO727 carbine built on an A1 forging with M16A2 rollmark




Matt Eversman and his RO727, and what appears to be a Surefire 6P in a barrel mount, and possibly an A1 lower forging




RO727 after the notorious "Black Hawk Down" incident on an A1 forging, notice that the M16A2s behind it appear to be on A2 lowers.  Notice too, that the RO727 has an A2 grip, which, while easily retrofitted, I wonder whether they would have bothered to switch the pistol grips when they dropped the 727 on a 653 lower.  The color of the anodizing on the lower, while lighter than the upper looks like it could still be Colt "preban grey", though it could also very possibly be "XM grey," making it a remote possibility that it is a 653 lower.  

Also note the large FA button with clearance cut on the M16A2 on the lower right.  

~Augee

Unfortunately the MIL-SPECs don't have detail information on the barrel profile.  The barrel information in the MIL-SPEC is exactly the same for the XM4 and M4A1.  I've never heard of the XM4 having a different barrel profile from the Model 727.  Both should have what became "standard" for the M4 profile.


The references I find to the Abu Dhabi carbine are the 723.  The 727 is not something I generally find referenced using that title.  The UAE purchased 723s and 725s, which is where this name comes from.  The UAE did not purchase 727s from my understanding.


This is irrelevant if we're talking about 720s, as XM4s were not the same as current production M4s.


See the difficulty in documenting through period photographs is the quality.  The configuration is shared by a half dozen weapons in the time period and we really don't know what the exact configuration of the 720/XM4 was.  Is the caption to the Matt Eversman photo yours or is it an official photograph with an official caption (not that those are 100% either)?  Because we could spar over what it is for hours and not get anywhere, because neither of us can really tell 100%.  You can't look at the barrel markings or lower receiver rollmark, etc, to prove or disprove the existence of a third weapon in play.  I'll agree now that you and I showed me to be in error, that 727s were definitely on the ground.  I was wrong there.


Negative, these would've had different model numbers.  Colt has separate model numbers to differentiate these differences, hence the existence of the Colt Models 726, 727, 728, and 729.

All of the pictures posted are appreciated, but there's basically no way to tell whether they are one model or another really.  You can't see the rollmarks, and there are various possibilities.  There's nothing in the MIL-SPECs to imply 720s didn't in fact also "suffer" from Colt's transitional period, as its clear enough that they were very different in principle from the subsequent production 920s.  Note that the date on the XM4 MIL-SPEC is April 1987.  



No less grainy then then some of others, and that looks like it could be an A1 lower.  This is the same picture setting of the Official US Army photo of the M16A2 on the old TACOM RI website.   Definitely has a different barrel profile.  The whole matter of the post-653, pre-M4 period can be a bit murky in my mind.

However, getting my dates wrong at the beginning does suggest that there was a mix for sure (which I suggested was nigh impossible at the beginning), because the US Navy SEALs and similar organizations were involved.

Great info here guys!
Thanks

Just to add more fuel to the fire:

In External Barrel and Handguard Temperature of the 5.56mm M4 Carbine, dated September 1994, pretty clearly shows a test weapon with a stepped barrel and fixed carry handle (the blueprint diagrams also show this).  The barrel is actually described as an M4A1 barrel at times.  It would be nice to get a hold of the XM4 development document mentioned in this one too.

A 727 barrel has a different taper before the notch cut.

It also has no taper under the handguards.

An M4 barrel tapers from .670 to .600 under the hand guards.

From how slight the difference is in Ekie's carbine guide, I have to say I think conclusively identifying one or the other from the available pictures would be impossible.  We're also still talking about the 727 and XM4 as well, not the M4.  The XM4 from all accounts appears to have been very much a transitional multi-variation weapon, much like the various small variations of the M16A1E1, also in development at the time.

Yes I know.

I'm just pointing out they don't use the same exact barrel.

Unfortunately, a great many of the references that exist that I've seen either contradict each other, or at best, muddle things, and make the model numbers in particular, difficult to pin down.  

Where possible, I'll try to cite references, however some information, is, by my own admission, hearsay, most of it based on information that I've farmed on this very forum, and from people who seem reliable in their information, such as csbar, Ekie, and ScottRyan.  

That being said, my understanding is that the XM4/A1 / RO720 development was separate entirely from the military use of the RO723 and RO727 type carbines.  "As early as mid-1982, the US government had expressed interest in a redesigned and upgraded carbine variation of the M16A2 weapon system...the government was looking to procure their second general-purpose carbine of the 20th century, which, like the  M1, M2 and M3 carbines...intended for the use of rear-echelon troops..." (Bartocci, TBR II)  Note that the XM4 specs and project, which most, though not all, sources seem to agree would have been designated the RO720 were not initially designated for use by Special Operations personnel.  

On the other hand, the SOCOM had not had a type-classified M16 based carbine since the XM177E2, which was classified as a submachine gun, and not a carbine.  Obviously, SOCOM did not desist the use of "shorty M16s," referred to colloquially as the "CAR-15," and the XM177E2 was replaced by the RO653, a COTS purchase item for SOCOM use.  It's my belief, though I'd be willing to recant if anyone can bring me a source; that SOCOM continued to use COTS RO723 and 727 carbines until the finalized RO921 (M4A1 Carbine) came on line.  "...when the XM4 project was initiated in 1984...carbines would be used mainly if not exclusively by support troops... However, by the time the M4 and M4A1 carbines went into production a decade later in 1994, the end users had become frontline fighting units such as the SEALS, Special Forces and Airborne Divisions." (Bartocci, TBR II)  It appears to me based on the evidence, that the XM4 project was a separate development project that SOCOM took a particular interest in due to its use of similar COTS M16A2 carbines, which they continued to use until the initial deliveries of the finalized M4A1.  



Again, according to TBR II (the most convenient, and only print, non-online, non-PDF, ect. source I've got in front of me), "twenty-five carbines were built using the few XM4 components that were then available.  The barrels used were standard Colt Model 723 chrome-lined 14 1/2" barrels, rifled with a 1 turn in 7" twist."  TBR II does not specify which barrel profile, the .625 lightweight, or .750 notch cut barrel, however it does have a diagram of possible barrel profiles that Colt examined to allow the mounting of an M203 grenade launcher on a .750 diameter barrel.  



I certainly don't doubt that the notch cut .750 barrel that would become the progenitor of the M4/RO920 barrel was the same barrel that was eventually used on both the 723 and 727, as well as on the 720/XM4.  

These two photos are the ones that I've seen most often connected to the XM4/RO720 label, notice that they both seem to feature the second barrel profile seen on the diagram above, which is what I was referring to when I was talking about the 720 having a different barrel profile.  It is more noticeable in the first photograph, however, I believe the second photo displays the same barrel.  Again, while the model numbers I'm using may be muddled, I would have to assume, regardless, that those are photos of XM4 carbine prototypes undergoing testing and trials.  





Also, note that they both utilize A2 lower forgings, a point I will touch on later on.  



I've seen references that seem to imply several different things about the "Abu Dhabi Carbine," including that they specifically requested A1 sights, A2 sights, or that the idea to make a .750 barrel that could accept an M203 were requested by the UAE, and found their way into weapons used by American forces.  I've seen the model number referred to as 723, 725, and 727 for the UAE order.  I have not seen any primary source information so far about the exact specs of the Abu Dhabi Carbine, so I would be extremely pleased to see some concrete evidence as to what carbines, to what specifications they purchased.  The bulk of my research so far seems to indicate to me that it was in fact the 727 that the UAE accepted, however, I'm more than willing to accept that I may be in error in that assumption.

Nevertheless, it seems par for the course to me that the Army, and Army Special Forces would have had a preference for the A1 sights of 723, they never really saw the need to swap between the A1 and A2 sights when the USMC requested match sights.  That NavSpecWar would at the same time, select the 727 with A2 sights when selecting COTS models.  I also believe that I've heard that the 727 carbines that were used by 75th Rangers were in fact diverted to them from a NavSpecWar order.  I cannot substantiate where I've heard this, and could be completely wrong, just throwing that one out there.  

Nevertheless, and counter to the information in TBR II; I would say at very least, that the RO727 is in fact the .750 barreled carbine with A2 sights, as examples can still be seen in service with the Navy, and listed in their inventories as "727s."  Also, regardless of whether or not a carbine with an S-1-3 FCG would be a 727 or a different model number, those that are and have been in service have S-1-F FCGs.        



Agreed, however I brought up the issue of barrel profiles referring specifically to the prototype XM4 barrels in the diagram and photos above, and making that distinction.  Again, I believe that those photos depict an RO720/XM4 prototype, and while later 720s may have adopted the 723/7 barrel profile, I usually refer to that barrel profile as a "720 profile" barrel.  This of course is my own informal and completely unofficial nomenclature, and could be the reason for some of the confusion.  Photos of carbines with similar barrel profiles are present and visible in SGMLee's photographs of the Reed Knight collection, and it would be very interesting if anyone who had the opportunity could examine one of them and report what features are present as well as the rollmarking.  

Incidentally, one of the "720"/XM4 photographs shows an Aimpoint Comp XD or Comp M in a QRP mount and gooseneck mount, which, leads me to believe (not as well versed on Aimpoint history from that time period) that the photograph is most likely from the early to mid nineties, at earliest, though one cannot preclude that they may simply be demonstration/promotional photographs, taken with a prototype after the current design had been finalized.  



The caption is mine.  I agree about the difficulty in using period photographs for interpretation, as well the difficulty in nailing down the exact configuration (not helped by the fact that it went through many changes throughout prototype development and testing).  However, another hobby of mine is WWII aviation research, if you want to talk about a bunch of nerds pouring over old photos with magnifying glasses, you should give that a try.    At least we're not worrying about color variances in orthochromatic film, and overexposures, and fading with age in someone's attic... though I guess I may have slightly touched on it with the differences between preban grey and XM grey anodizing.  Anyways, it seems to me that we're all here to learn, and any more information, or even possible speculation is great for research, and advances our cause of learning everything we can about the pre-M4 carbine types.  



I believe you may be correct on that note, looking over my Colt model numbers again, it seems that there are quite a few commercial and export models that vary in model number with the FCG.  However I maintain that the RO727s accepted by both NavSpecWar and 75th Rangers were S-1-F FCGs.  



Definitely, there's no way to tell without a shadow of a doubt some things from the existing photographs, most information that we can glean from them is gross details of configuration, anything else is hypothesis or inference.  

There's not necessarily anything to suggest that the RO720 could not have been built on transitional A2 marked A1 lowers, and I'm almost certain at least some of the prototypes, particularly the very early generation prototypes were built on A1 lowers.  Nevertheless, because the 720/XM4 was specifically being developed to be a type classified variant of the M16A2, while the 723 and 727 were simply commercial/export models purchased COTS, that especially as development on the XM4 got more advanced, that XM4 prototypes would be almost uniformly built on A2 forgings.  Again, the photographs above of the XM4 both clearly show A2 lower forgings.  On the other hand, the use of A2 marked A1 lowers in COTS production, including the RO723 and RO727 is well documented, and easy to verify even with a visit to subguns or autoweapons, and looking at the factory new M16A2 carbines being sold, properly marked M16A2, but clearly on A1 lower forgings.

The carbine in the photo is without a doubt an A1 lower forging, and the configuration is an interesting one.  It appears from the photo that the rifle has an auto sear pin hole, however the configuration with a lightweight 14.5" barrel and A2 sights is a bit unusual.  To be perfectly honest, just because it's on an Army website does not at all make it so.  Sometimes, completely the opposite.  I've seen some ridiculous things on Army websites, you have to remember that it's very possible that whomever put the photograph up did a simple image search, and posted what they could find.  The people who often put up those websites are not all the concerned about the minutiae that we are.  

However, if it is in fact an accurate photograph, there's a small possibility that it might depict one of the first twenty-five XM4 carbines that Colt literally threw together out of parts they had on the shelf.  Otherwise, it could be a simple commercial or off-brand (i.e. Bushmaster, ect.) carbine, or maybe even an Airsoft gun.  

~Augee

I don't like you use of terminology here.

Nothing is "descended" or "a variant of" an M16A2.

An M16A2 is a specific weapon that is part of a larger family tree.  It does not have its own family tree with variants branching off of it.

These Colt carbines are part of the AR-15 family and are on an equal level as a M16A2.

You are saying the M4 came from the M16A2.  

I could argue (and be more correct) that the M4 is descended from the first Colt Commandos in the 1960s.

Due to this, we give every variant of an AR-15 is own spot in the family tree.  This is the most correct terminology.

Scott,

I'm going to have to respectfully disagree, it was a long post sitting in front of TBR II writing that post, so I may have fuddled the language a bit in that last paragraph, I don't generally proofread my ARFCOM posts, but I fundamentally, I do consider the the AR15 family of weapons to be more of an evolutionary lineage, than a distinct and discreet collection of weapons.  

Granted, the Colt AR15 family is a convoluted tree, but I do tend to consider it to be something of a tree, with branches that come off of it, as well as evolutionary dead ends, like the RO608 survival rifle.  

Perhaps one of my biggest problems is in assuming others recognize the same colloquial use of nomenclature as I do, and should make these things more clear, or define what I mean by certain terms, which is my own fault.  However, when I generally refer to the M16A1 series or family, I'm not talking about the RO603 rifle, but the Colt classification.  It seems clear to me that Colt also considers certain rifles to be derivatives and variants of base weapons systems, as in the "M16A1 5.56mm Weapons System" poster on page 287 of TBR, and the "Colt M16A2 family of weapons, circa 1987" on page 19 of TBR II.  

I refer again to the quote from TBR II above stating: "As early as mid-1982, the US government had expressed interest in a redesigned and upgraded carbine variation of the M16A2 weapon system."  

You'd be correct in saying that the XM4/M4 Carbine is derived from and benefited from work done on the Colt Commandos of the '60s, but it is still essentially derived from an M16A2, you could call it the M16A2 version of the Colt Commando, M16A2 in Colt's terms, not USGI terms.  I try to be fairly clear when I mean a weapon in terms of USGI nomenclature, and usually try when possible to use Colt model numbers.  Perhaps rather than talking about the M16A1 and M16A2 family, I should refer to them more in terms of 600-series, 700-series, and 900-series.  

Perhaps I should try to make a flowchart of the Colt AR15-family tree.  IMHO, a type-classified variant, such as the M16A2 or M4 Carbine should constitute a benchmark in the family, however, I do believe that there are branches of variants that are derived from other variants.  

In terms of whether one rifle should be considered a derivation of one or the other, the question that really needs to be asked, is could one variant exist without another?  I believe in the case of the M16A2 and M4 Carbine, without an M16A2, there would be no need for the M4 Carbine, they may have chosen to refine the RO653 further, and it may have ended up being type-classified as the M4 Carbine, but nevertheless, it would not have been the same development process or the same rifle.  I would maintain that without an M16A2, there would be no M4, making the M4 a derivative of the M16A2.  

This of course, is all speculation, based on my way of looking at the development of the AR15 family, and I certainly do not begrudge you your view of the M16A2 and M4 as equals, seeing as how product development is not an organic family, no one can really be right or wrong, it simply depends on your way of looking at it.  

As an addendum to my above post, regarding the Abu Dhabi Carbine, from TBR:

"...Colt M16A2 Carbine made for AbuDhabi (Colt model 727)...The model 727 features...both AUTO and BURST capability.  Colt's is enthusiastic about the model 727 because, unlike the XM177E2, the user gives up very little indeed in terms of accuracy and velocity to gain the versatility of this impressive "package".  The 727 is a decided improvement over the light barreled model 723, and Colt's is moving towards the new version.

"  At the time of this writing, Colt's has produced between 30 and 40 examples of a US military trials version of the Abu Dhabi Carbine, officially called the XM4."

Note that TBR was originally published in 1987, making it relatively contemporary to early XM4 development, and seems to indicate that the 727 (A2 sights in the photo) was the basis for the XM4, as well as the "Abu Dhabi Carbine," though not mentioning what the Colt model number for the XM4 was.  Mind you, this is only one source, and by no means the final word.

~Augee

I am generally considered to be one of those people.


Not initially designated for Special Operations use in 1987 sure, but 6 years after the MIL-SPEC is issued?  I find it hard to believe that it was impossible for a unit like the 75th Ranger Regiment to acquire such weapons.

Secondly, the "M16A2 Weapon System" is a Colt term.  The US Army has never referred to the M16A2 as a system of systems.  


Its R653.  The RO terminology doesn't come into usage until the 1980s.  No one had type classified carbines of any type after the M2/M3 was removed from service.  The XM177 series was type classified as a Submachine Gun


Again, there's no indication here that those units weren't recipients of trial weapons before the start of production in 1994.  All it says was that the doctrine changed between 1984 and 1994.  The same doctrine had been true for the XM177 series.  It was designed primarily for use by RTOs and other troops in need of a lighter handier weapon and not in need of a full size rifle.  The AAI Tunnel Gun was designed for tunnel rats, but were quickly acquired by LRRP units for use on ambushes.  Its really not that hard for small quantities of extremely limited weapons to become available to units who can make the case.  


Available when?  In 1984?  Because again, these were test M16A2 carbines in 1984.  There isn't an XM4 until 1987 when the MIL-SPEC is issued.  Furthermore, there's 9 years between then and Gothic Serpent.


I'd like to see the bulk of the research, since it has seemed pretty clear that it was the 723 for some time to me.  I go by what model numbers are linked to the UAE, and the 727 has not been one of them.  Does TBR II link the 727 to the UAE?  


This would be the only way the 727s would have got to them, since the US Navy has been the only one concretely known to have put in orders for them.


They would've been a different model.  Every instance I've ever seen where there has been a debate, some source has turned out to be wrong.  There is no precedent of Colt assigning the same model number to weapons with different trigger groups and a huge one of assigning numbers in sequence to differentiate such subvariants.  My point there was that if the 727 was S-1-F, there would have been absolutely no reason to replace the lower with a 653 one for this capability.  The 723 was also S-1-F.  If there was swapping going on it was because they had gotten 720 uppers and needed this capability.


See above.


As stated before these are Colt terms.  Colt called its gas piston collaboration with Olin-Winchester the M16A3, and calls all its flat tops M16A4s regardless of trigger group.  This has absolutely no bearing on the US military understanding, and how it treats relationships.  What Colt saw was creating a series of carbine variants based on its 645 type.  What the US Army wanted was a carbine that shared a commonality with its primary service rifle for ease in training, maintenance, and supply.  The M16A2 has never been described as a system of systems or "family" by the US military.


That's how Bartocci words it.  Its not necessarily how it was phrased in reality.  See above.


Doesn't work.  The M16A2 is in the 600 series.  Colt terms have no bearing on the US military or how it develops requirements and subsequent systems.


The M4 was going to be whatever was designated next in sequence.  You can't say that the 653 might been type standardized as the M4 and then say that without the M16A2 there would've been no M4.  Without the Colt 645 there would been no Colt 720.  The M16A2 would've been whatever came next and so would have the M4.  Colt's development chain has no bearing on the US military understanding which is, by definition, essentially arbitrary.  

Thatguy96,

Not doubting your reliability as a source, nor am I trying to say for certain that you're mistaken, just letting you know that some of my information, though it may be hearsay, comes from sources that I tend to consider decent sources.  I'm more than willing to admit when my information is hearsay, to let you know.  I'll admit to not having done as much primary source research as others may have, possibly including yourself.  Most of my research on the subject has been through secondary sources, however, I tend to think that I've got a fairly high bullshit threshold when dealing with secondary sources.  

I certainly don't think it would have been impossible for for 75th Rangers (BTW- I accidentally identified 75th Rangers as a Battalion rather than a Regiment in my above post ) to get a hold of trial weapons, nor did I say that my use of "M16A2 family" was a military designation, see my response to ScottRyan above.  What I said is that I don't feel that the evidence indicates that the XM4 was the issued weapon during Gothic Serpent, nor do I feel that it really, other than an example or two, was a weapon that went in numbers to SOCOM.  This is speculation based on my experience, and what I can see from the sources, which, for me, do not include perusing SOCOM's purchase orders and deliveries, I simply haven't the time or energy.

I already said that "I do not believe" that they accepted them until the RO921 came on line.  My reasoning for this is an extrapolation based on the fact that I maintain that there were both 723s and 727s in the units as COTS purchases, and that they were sufficiently similar to the XM4/720 for them not to worry about refitting with XM4s.  Perhaps the 723s and 727s were replaced with XM4s late in service, as the existing COTS weapons became unserviceable, nevertheless, I speculate that in general, they simply continued the use of the 723s and 727s.  

You say that there is no indication that they did not receive these weapons, which I agree, I cannot provide that documentation proving they did not, however, I've also not seen any convincing indication that they did.  Most of the time when I see XM4s referred to in service, I am dubious, as the majority of the sources seem to misidentify other models as well, and seem to be confusing what appear to be COTS carbines for designated XM4/720s.  

In the case of the XM177E1/2, and while I've not researched it closely, the AAI Tunnel Gun; it represented a new class of weapon, and a new capability which LRRP and SF units did not have already.  On the other hand, during the timeframe that the XM4 was being developed, SOCOM units were already equipped with the same capability that the XM4 offered.  I would suggest, speculating again; that the doctrine for employment of the XM4 didn't necessarily change, but rather that the priority changed, which TBR II talks about, and how the priority of development shifted from parts commonality with the M16A2, to absolute reliability for front line combat use.  Which essentially becomes a game of semantics, which I'd like to avoid (I noticed that jab about the "RO653," again, I sometimes get excited about this stuff, and I don't proofread it. ) however, I feel that the XM4 development and the employment of COTS 723s and 727s happen in parallel, and that one was not related to the other until the XM4 was more or less finalized, and became a direct replacement for the COTS carbines that already existed.  What started out as a weapon for support troops became reflagged as a weapon for use by "high speed" units, as a projected replacement for existing COTS carbines in the inventory.  

Just to address the terminology again, briefly, as I said, if what I write is unclear, my apologies, however, what I meant in the statement: "SOCOM had not had a type-classified M16 based carbine since the XM177E2, which was classified as a submachine gun," does not say that the XM177E2 was type-classified as a carbine, which you correctly point out had not happened since the M3 carbine prior to the M4, but that it was an AR15 carbine variant, and the last carbine variant to be type classified, as we have pointed out, as a submachine gun, and not as a carbine.  

As for the existence of Colt prototypes in 1984, I'm not debating dates at all particularly, or when the XM4 MilSpec was issued.  

TBR I is the main source that I have linking the 727 to the UAE, the quote is at the bottom of my response to ScottRyan above.  Again, secondary source material is all that I've been able to provide for you, however, given that the source is from 1987, contemporary to the era that we're discussing, I give it a fairly decent amount of weight.  Like I said, I too have heard conflicting information that it was in fact the 723 that was purchased by the UAE.  I do not have access to the primary sources to prove or disprove either.  I have so far chosen to give TBR I some extra weight in my consideration, because it has proven a relatively good source of information, and it is contemporary, so information that we may currently be digging for, was current when it was written.  This does not mean that the author could not have erred, and I would be very happy to see primary sources, or even secondary sources of equal weight that refute the statement that the RO727 was the Abu Dhabi Carbine.  I will be happy to recant when the documentation is presented.  You don't even necessarily need to bring it to me, point me to where I need to dig, at least, and I'll come back and tell you that you were right and I was wrong.  

As far as the Rangers getting a hold of 727s, I don't want to indict anyone, and put words into their mouth, I believe it was Ekie, though it may not have been, I have already admitted that I don't remember very well whether I heard it, so it may be dubious information, but I seem to recall having heard that the RO727s in 75th Ranger Regiment's possession were redirected from a Navy order.  I'm well aware that the 727 was primarily a Navy purchase, however I'm fairly certain that some did find their way into Army hands.  

I agree, that a different FCG would have probably meant a different model number, I concede that point.  I'm not sure why this whole issue of swapping lowers got brought up, other than someone mentioned the possibility, nevertheless, I don't think that it happened.  As you said, if the Rangers had accepted RO727s, which I believe they did, they would have had no need for swapping lowers, a point that I have maintained throughout.  I have never implied that any swapping went on.  

Again, with regards to Colt designations and military designations and model numbers, I see this as an issue of semantics.  If it would streamline our discourse for me to cease using them, then I will, however, I still consider it to be a valid way to describe the evolution of the AR15.  I have made no pretensions that M16A1 and M16A2 families are military designations at all, as a matter of fact, I've taken pains now in a couple of responses to make it clear that I'm not referring to military designations.  

You're playing the semantics game again with the whole "the next carbine type-classified would have been the M4," you're correct, and I pointed that out once already.  Yes, the next carbine in line would have been the M4, I'm aware of the military system of nomenclature, and because, as you note, it can sometimes be arbitrary, and not reflect the development history of a system is one of the reasons that I tend to favor Colt's interpretations of weapon system families.  I'm not talking the military designations, I am saying that the M4 system as we know it, to encompass RO920, RO921, RO977; in the current state in which exists could not have existed if the M16A2 family of weapons systems, in its present form had not existed.  I'm not doubting that that other weapons may have eventually been given those designations if the development had not taken the path it did, but I am defending my contention that the M4 weapon system is a derivative variant of the M16A2 weapon system - Colt designations, not military designations.  I'm talking about the fluid evolution of system development, not the bureaucratic assignment of nomenclature, of which Colt is not fully innocent of, either.  As you pointed out, they have tried to anticipate military designations in the past and failed, for that reason I find it most helpful to refer to model numbers, however when the model numbers are the point of contention, things can become confusing.  

That Bartocci phrased it that way, as you put it seems to indicate to me that he's thinking along similar lines to the way I'm thinking of it.  Dunno, could be wrong, crsbar?

I hope you realize that I have no ego tied up in this , I study these things as a hobby within a hobby, my primary joy is optimizing a modern rig, and I have several optics heavy M4 based rigs.  My interest in these retro carbines is a combination of my affection for the M4 Carbine, combined with my zeal for history, and to that end, despite the numerous more modern rigs I've got, I've got an RO727 clone, and an R653 clone, but when priority for parts or funds comes, they go to my modern rigs.  Sorry if that's retro blasphemy, but it is what it is.

Regardless, as I said, I do love studying history, and I got my degree in history, so I am pretty well familiar with how to do research, and how to pick through a myriad of conflicting sources, and to extrapolate based on sketchy information.  My interpretations are exactly that, my interpretations based on what research I dabble in, which I am no Ekie, or CaptRichardson, or crsbar.  

Believe me when I say with sincerity, I welcome you, I invite you to prove me wrong, however, don't expect me to simply accept "well, I know this" as sufficient.  I welcome the discussion, and the disagreement motivates us all to look deeper, and reexamine our preconceived notions, to look for flaws both in our own and in others' logic.  Honestly, you needn't sit there and directly quote text like I did for me to believe you, I try to when possible out of force of habit, nevertheless, if I say something you disagree with, and you say, "hey, I read in this document, or this source, this information which refutes/disputes/contradicts your contention," then I can check it out and say, "ah, I was wrong.  Cool, I learned something."  But please, produce something other than just more hearsay for me to go on.  

Discussion and debate are difficult on the internet, with nothing more than words and emoticons to convey our tone and attitudes, and I hope no one is detecting any rudeness or enmity in my posts, and hopefully it's not being directed my way, either, because it's simply not productive.  I want to learn about carbines, not prove how much I know about them. Unless ScottRyan thinks I'm just too much of a noob to even be debating this with the likes of y'all, , j/k, Scott.  

~Augee

I know what you are saying but phrases like "Colt M16A1 Weapons System" are an advertising term to put guns in certain categories to make it easier for less versed people to understand.

Phrases like "Colt M16A1 Weapons System" do not explain what is really going on model by model.

I know the military uses certain nomenclature like this, but again, it is so less versed people can understand.

Great thread, unfortunately I lack the time for a good post.

Info on 700 series carbines in US Military use is hard to come by.  However the US Navy use of the 727 is well documented.  

The carbines used by the 75th INF in the early 1990’s is not so straight forward.  As Augee pointed out the 720 has some distinct features that the carbines carried by the 75th lack.  Most importantly they were built on USGI M16A2 lowers while the carbines in questions had lowers machined from A1 forgings.  In addition of have seen no evidence of any type that the 720 was ever issued out.

The best source of info are from guys that were issued these weapons during this time frame that have a real interest in firearms and know the difference between say a USGI M4 and a Colt export model.  Thing is, for every serviceman like this there are 100,000 more that have not a clue, nor even care.  Try doing archive searches on posts by:

2011BLDR
Sinister
want2race

This is a very interesting post by 2011BLDR in regards to the Navy 727:

http://archive.ar15.com/forums/topic.html?b=3&f=118&t=211000

I served  between 1980- 2000.  Most operators in 1993 had 723 carbines that were cots purchases.  In the  late 80's my unit did  test  the XM 4. Most people did not like the A2 sights.  The rifles we tested had the current M4 type profile barrel.  I was surprised to see the picture of the Rangers with the 727 carbines.  We did not like them and we purchased the 723 because of the  M16A1 sights and also continued to use updated 653 carbines with1/7 replacement barrels and a few 733s.  I was not issued a 727 until 1995. I bet that the Rangers purchased the 727 cots because they wanted all of their weapons to have the same type of sights.

Regards Joescuba

Thanks, Joescuba!  

Could you tell me more about what you did insofar as testing of the XM4?  What did it entail?  Do you by chance remember what they were rollmarked?  Were they S-1-F or S-1-3 FCGs?  Two or four position stocks?  

Are you able to tell us what unit, or what organization you were with?  I'm afraid I don't remember specifically?  Under what conditions did you end up being issued the RO727?  

I'm assuming that the upgraded 653s used the lightweight 723 barrel?  Or was it a .750 barrel with 203 notch?  

I realize this is a lot of esoteric questions, but I'm genuinely curious!



Just as an addition, this photo from SGMLee's photo essay of the Reed Knight collections shows what I believe to be an XM4/RO720 prototype.  I would love to get a chance to examine that rifle closely, it's on the right side, under the XM177E2.  

It's got the "720" barrel profile I was referring to, and visible on the diagram from TBR II, as a prototype barrel.  Notable is the A2 lower forging, and it appears to be marked with PROPERTY OF/US GOVT rollmarks.  Compare with what appears to be a 653 below it, with what appear to be commercial (COTS) rollmarks.  

Any thoughts anyone?

Thanks,
~Augee

Thanks!  That's a great help, and as Ekie said, the best sources are often the ones that carried them.  

No problem if you feel a little reticent in saying which unit you were in specifically, and I've seen enough of your posts in the forums not to worry about bonafides.  I was just not sure if you'd said what Group/unit/ect. you had served in.  It's not vital information, and as a soldier, I understand your desire for discretion so I won't push it, but as a historian, I'm always trying to trace who used what, when, which led me to asking.  

You should have seen me when I got invited to see an ODA weapons locker overseas, I don't think any of them had seen someone put their nose into a weapon and take pictures of forging codes and proof markings.



Incidentally, a lot of them had older M4A1 lower receivers marked "Colts MFG" rather than "Colt Defense."  But, for example, I can now document that at least one unit, did, and likely still does use a LaRue Steath upper.  Not that I ever had any reason to doubt it, but documentation is still different than simply believing it.  

Thanks again!  Great information, it sounds like then it was possible that an operator here or there may have had an XM4/720 but wouldn't have constituted an entire unit or team switching over?

Do you happen to remember when you started getting M4A1/RO921s?  Were they considered to be a direct replacement for any item in the inventory, or were they simply issued?  

   

Here's a better picture of Estella, by the way.  Thanks for the compliment!  Sadly, neither of them still live with me, but we raised her and one of her brothers almost from birth, this photo is of her less than a year old!  

~Augee

In "Small Arms Today, 2 Ed.", Ezell stated that Abu Dhabi ordered 20,000 Model 727 in 1987.

BTW:  Aimpoint 5000 were on the market prior to the Fall of 1993.  I can't remember when I bought mine used from a fellow IPSC competitor.  I want to say 1992...early 1993 at the latest.  I had to send it back to Aimpoint in the Spring or Summer of 1993 because of a broken switch assembly.  They replaced the entire sight.

Thanks, the Aimpoint website lists the Aimpoint 1000 I've got as having been released in 1987, and it looks every bit the piece of '80's technology!  I think I would have preferred a 3000 or 5000, but I kind of fell into the 1000, it came with a 1911 I bought for another project.  

To add another interpretation (I told you my 727 was the configuration mule!), here's my 727 back to black furniture, without the light on one a new NDS A-1 lower I just got.  The upper's black, so the color's way off, but I'm seriously considering getting an A1 lower finished in preban grey and dumping the CMMG clone barrel, and going bonafide 727.  For some reason, I just love the look of the A1 lower on a fixed carry handle carbine.  

This lower is actually destined for a 654 build, woe is me, I guess I'll have to send more money to NDS!  





~Augee

P.S. in all the debate over nomenclature and development, no one has yet been able to help with my original question... does anyone want to try a whack at it?  

Are you positive the mount is that extended, and not just a shadow?
Looking at the rings, the scope looks like it would fit a standard mount...

Nope, not sure at all!  It might be extended, it might not, but I haven't seen a carry handle mount that long, but I haven't been around too long, I was eight during the time period in question.  Just wondering if someone else had seen something like it.  

Here's a slightly different crop I recently found:



Still kinda hard to tell, though.  

~Augee

ETA: Well whadya know?  It's not a different crop, looks like it's a different photograph.  Somebody probably blinked or something.

That does look extended.

Any chance a regular mount was re-drilled to move it further forward?

lots of good stuff here..

I dont think its extended Augee.

too me it looks like a shadow especially if you look at the shadow at the rear of the scope against the guys  gear.  Seems like just one of those flukes of photography. I looked in  THE COMPLETE BOOK OF US SNIPING by Peter Senich and didnt see anything  either not that it has everything.  But it has a vast  amount of odd mounts extended or not that where made inhouse by armorers and the USAMU to try to make something workable for the M16/A1 to have longer range. I didnt se anything like that in it.  All the ones I see....(dont know how to describe by typing)  but they arent like that. just my opinion

There were three scope mounts in common usage in the early 1990's.  There was the Leatherwood, the ARMS #2 and then a cheapie one that everyone at the time offered.  I checked and Bushmaster still carries it:

http://www.bushmaster.com/products.asp?cat=20

It is the ninth one down for $21.95.  


That is the mount you see in the pictures being used by the Rangers.

I had one at the time, and I don't recomend them.  The ARMS is much better and widely available at the time, and I will be using them on my 723, 733, 727 clones when I ever get around to building them.

I stand corrected   So you  are certain its not a shadow? I guess thats why I wear glasses

Can you see it here?

How about here?

Well, now that the extended mount has been established, any leads on the scope?

Or, anything on the model number issue?  Still interested to see what anyone else has to say on that subject.  We've now got at least circumstantial evidence that XM4s did in fact find their way to operational units, though in limited numbers, which very possibly could have been RO720s.  

~Augee

Bump to keep a great thread alive.

Curious if Joescuba and/or others can confirm which barrel profile his 723s had?  I've read that early 723s had a pencil barrel and later 723s had a M4-style barrel?

There are a couple pics on Militaryphotos.net of an Army SOF operator in Somalia holding what clearly appears to be a 723 with M4-style barrel here (halfway down the page):
http://www.militaryphotos.net/forums/showthread.php?t=109339&page=21

YMMV.

Will

Hi Augee.  I 'm sorry, I thought I had already told you about the scope.  I quess I must be getting a.d.d.  That scope is the Leupold M3 that came on the M24 sniper rilfe. They have installed the 5.56 ballistics cam.  Even though the BDC was for the 55. grain bullet it was often used during this period.  Its hard to make out because of the cammo paint, but these were in common use, from Desert Storm on.  We used the ARMS scope mounts with STANAG rings in my unit , but some units used the extended rail and the M3 rings as in the picture. That would be a neat build.  Now if you could obtain a vintage OPS INC or KAC supressor, that would be the cats meow.

Cheers, Joescuba.

Thanks, Joescuba!

Great to finally get an answer!  I'd love to build that carbine... but I don't know if I can justify it to myself financially, it's not really an ideal DMR configuration anymore, and I almost feel like it would be a waste.  

Because I'm OCD, I'd have to go for a real deal Colt 727 upper, an A1 lower, SBRed, and refinished in Colt grey, and a thousand dollar scope...  Though an option might be to get a stainless barrel, and try to find or make a carbine length service rifle FF tube that looks like standard carbine HGs... oh dear, I'm scheming again.  My imagination works faster than my paychecks... Maybe if I build an SPR I can switch the M3 in and out...

Honestly, most likely, I'll buy a lesser (cheaper) target scope to get the proper "look," and call my Gothic Serpent 727 done.  As for suppressors... well, a HALO will have to do,  

If I'm gonna get a KAC, it's gonna fit my M4, and if I get an OPS Inc. it's gonna fit that SPR that dances through my dreams late at night.  

~Augee

Yes it would take a chuck of change to purchase that glass.  They were a bit over kill for the urban setting.  They (Rangers)were just using what they had on hand. The U.S. did use some Hensolt ZF 4x24 scopes in this period.  

Regards, Joescuba