current configuration

Dude, nice.

+1

What sling is that?

Sheriff of Baghdad B-Sling.

Thanks!

It's a great sling.  I'm torn between it and a non padded VCAS.

Is it possible to use with a receiver end plate mount?

~Augee

You can.  You would have to cut the end off and use the tri-glide that comes w/ it.  Once I get my new sling mount I'll be doing that.

Noob question.  What is the difference between the mk18 vs the cqbr? Is it the mk18 rail system w/o FSP(isnt there a mk18 FSP model?  vs the cqbr's use of the kac ras with a fsp?

I was under the impression that the Mk18 is an entire rifle, while the CQBR is just an "upper." I think the Mk18 only had the RIS/RAS as rails too, but I could be wrong. I'm sure Augee will be here soon to explain it all.

The MK 12 and MK 18 were both spin-off weapon systems from the SOPMOD M4A1.  

In many ways, between the RIS and the "sudden" realization that you could pop two pins and have a completely different rifle, the SOPMOD Accessory Kit and companion upper receiver groups were the beginning of the "modular assault rifle" concept.  

The idea was that the M4A1 could be adapted to both a CQB role and a sniper role by using different upper receivers.  The first was the Special Purpose Receiver, or SPR.  The other was the Close Quarters Battle Receiver, or CQBR.  

The story of the MK 12 SPR is pretty well known - the Special Purpose Receiver was developed, and the SPR-A and B became the nucleus for the MK 12 MOD 0 and MOD 1.  At least part of the reason for "spinning off" the MK 12 SPR into the Special Purpose Rifle were to provide a better trigger for the SPR, and NSWC-Crane's firm opinion that the MK 12 should only be fired with a fixed stock.  

Nevertheless, the MK 12 MOD 1 SPR was considered unsatisfactory by some, and the Special Purpose Receiver concept revisited, and ultimately resulted in what is colloquially known as the "Recce" carbine.  Inasmuch, an argument can be made that the closest to "correct" name for the "Recce" would in fact be right back where we started - "M4A1 SPR."

Either way, the MK 12 SPR became "widely" issued to SOF, then some years later, was picked up by the USMC as a replacement for the PWS-built SAM-Rs.

On the other hand, the CQB component of the M4A1, the CQB Receiver could still be a "drop in" module for the M4A1 lower, and therefore continued to be used as such.  Many end-users are seen to have both a 14.5" and 10.3" URG as part of their "deployment kits" using a single M4A1 lower using an H2 buffer.  

Nevertheless, the CQB Receiver was spun-off into a complete weapon system to replace some of the MP5s in service into the MK 18 MOD 0 CQB Rifle, known as the MK 18 MOD 0 CQBR.  Most notably, they were issued to shipboard VBSS teams, as well as the Coast Guard,  but for the most part - not to SOF, as SOF was not using the complete weapon system as issued by NSWC-Crane, but simply the 10.3" URG in place of the 14.5" URGs on their M4A1s.  

One distinguishing feature of both "spin-off" systems is that almost all of them were built on refurbished M16[A1] lower receivers without the additional receiver extension and pivot pin reinforcements of the A2 lower.  NSWC-Crane, rather than purchasing new M4A1 lower receivers to modify to build new weapon systems is simply recycling old lowers that needed new upper receivers anyways, and thus keeping their costs down.  As such, almost every MK 12 or MK 18 that you will see will be sporting an A1 style lower, a point often missed by clone builders (the only "appropriate" lowers currently available are older PWA and SGW lowers and new production NDS lowers).  

Another difference between the "spin-offs" is that they are issued as complete weapon systems with accessories and optics as part of the "package," while M4 CQB Receiver assemblies are intended to be accessorized based on user preference using the items provided in the SOPMOD kit.  

When the MK 18 was "spun off" from the CQBR, they were accessorized with then-current SOPMOD accessories.

The rail system was the KAC M4 RIS, the muzzle device for the M4 QDSS was standard, the VBL was the Surefire M962SW02, and the Aimpoint CompM2 with Wilcox mount was designated the ECOS-N.  The Crane Enhanced Cheekweld M4 Buttstock and cut carry handle style BUIS were also popular.  Around this time, both components were also contracted to LMT for manufacture.  

Since the MK 18 MOD 0 used standard SOPMOD accessories, for a short time, the MK 18 MOD 0 CQBR system was set up almost identically to M4A1 CQBRs in the field.  Visually, the only way to distinguish them was the lower receiver group and the end-user.  Many MK 18 MOD 0s were also laser engraved on the right side of the magwell with the NSWC-Crane MK 18 markings we well.  

The interesting thing about the whole MK 18/M4A1 CQB Receiver deal is, however, that the "MK 18" nomenclature (usually incorrectly displayed as "MK18 Mod 0," without the space and with the "MOD" in lower case letters - yes, I looked up the reg, and it states that when abbreviating Mark 18, Modification 0, "Mark" is abbreviated to "MK," all caps, with a space between the number, and the same with "Modification" and "MOD."  Alternatively, all mixed case letters can be used, "Mk 18 Mod 0," but either way, they're without punctuation.  (MIL-STD-1661)  This is counter to the Army way of designating weapons, with no spaces or dashes, i.e. "M4A1," not "M-4A1" or "M4A-1.") became so popular in the gun community at large, that many end users themselves began referring to their M4A1 CQBs as "MK18s."  

While the argument can be made that "MK18" has become the common nomenclature in popular use, and that everyone recognizes and understands it, from a technical standpoint - the MK 18 MOD 0 and M4 CQB Receiver have different NSNs as well.  Another thing that seems to be worth clarifying - my use of the terms "M4 CQB Receiver" and "M4A1 CQBR."  Because there doesn't seem to be a lot of clarity in whether "M4" is used generically or "M4A1" is specified, my habit has tended to be to refer to the receiver alone as the M4 CQB Receiver, because "technically" it can be mounted to any M4 weapon system, whether "standard" (RO920 M4 Carbine) or M4A1 (RO921HB M4A1 Carbine).  When mounted to an M4A1 lower receiver, however, it can be specified as an M4A1.  This is not strictly "official," but a distinction I personally make following military nomenclature conventions.  

Anyways, back to the story -

Since the MK 18 MOD 0 was type-classified as a complete system, it has remained relatively static, and still uses the ECOS-N and VBL II SOPMOD components.  On the other hand, the SOPMOD program has continued to evolve, and the ECOS-N and VBL II have both been replaced.  Furthermore, Increment 2 of the SOPMOD program introduced the DD RIS II to replace the KAC RIS (though many units were using the RAS already).  

Because the M4 CQB Receiver was a component part of the M4A1 SOPMOD, it too received Increment 2 accessories, including the RIS II.  The MK 18 MOD 0, however, did not.  

In a confusing bit of commercial naming and official nomenclature, however, in order to distinguish the 9.5" RIS II from the 12.5" RIS II, Daniel Defense named their winning submissions the MK18 RIS II and M4A1 RIS II respectively.  And though commercial marketing nomenclature has no bearing on military nomenclature, the assumption was that M4A1 CQBRs using the DD MK18 RIS II were then "MK18 Mod 1s."  

Again, it became a case of popular nomenclature "MK18 Mod 1" becoming so widespread that even end-users assumed that since everyone else was calling it a Mod 1, it must be a Mod 1.  "MK18 Mod 1" is also a lot easier to say and type than "M4 CQB Receiver with SOPMOD Block 2 RIS," and, well... most people aren't as anal as I am.  

On the other hand, I have been able to find no mention in any official documents, manuals, contracts, or supply documents a single mention of a "Modification 1" to the MK 18 weapon system.  The closest I have found is that the U.S. Navy and NSWC-Crane appear to be re-barreling MK 18 MOD 0s with 14.5" RO920 barrels systematically - something that would probably warrant a "Modification 1" designation, but does not appear to have been granted one.  As a matter of fact, supply documents seem to instead be simply referring to these modified MK 18 MOD 0s as M4A1s, despite the fact that they're built on M16A1 lowers, and lack the now-standard RO921HB profile barrels.  

Another interesting animal is the "10.3" EOD carbines," many of which appear to be built on RO727 lowers with M4 CQB uppers.  Would this then make them "Model 727 CQBRs?"  Or has the "Model 727" nomenclature been fully dropped, and RO727s now re-designated "M4A1?"  

As you can see... clear as mud.  

~Augee

By the way - the short moral of the story is:

The combination of the high OPTEMPO and TTP turnover of the Global War on Terror and the crippled, Power-Point-dependent bureaucratic morass the military has made of itself, equipment is literally changing faster than "powers that be" responsible for naming things can get a name approved.  

Pieces of equipment can literally be issued, used in combat, and become obsolete before they even have a chance to name it.  

A great example is the TA31F ACOG - it was being fielded and used for years by combat units with no real nomenclature before someone managed to come up with additional requirements that ended up in the TA31RCO and it was bestowed the "official" name of AN/PVQ-31, which literally no one but me uses.  

Another good example is the M68CCO, which they appear to have given up on keeping up with the changes in models between the CompM, CompM2, and CompM4 in the last ten years, making for [not actually] hilarious situation in which a unit requests "CCO batteries" for their CompM4s and ends up getting drop shipped a case of 3v batteries.  

~Augee

In the USMC, the TA31F was designated the "ACO".  The ACO was officially replaced with the RCO, but could still be used as long as they were serviceable.  I personally saw a TA31F in use back in 2006.

I think with the M68, there is a reason for it.  The big Army got funding to buy an optic for pretty near the entire force.  If suddenly a whole new model were to be much better(E.G., Comp M2, Comp M3, Comp M4) and they were to ask funds to replace their new optic, that would not go over well.  But if the new optics were also "M68CCO"s they can just keep buying those.  Sort of like how the Army got funding for the M110 by declaring it was going to be their only new sniper rifle.  Then after they got the M110, they couldn't ask for money for new M2010s, so they 'upgraded' M24s into M2010s.  Easier to get money to upgrade, then to beg for new weapons.

I agree - this would be the bureaucratic morass.  

That's somewhat tongue in cheek, but the point is that under "calmer" circumstances, and by "straight book" doctrine, the CompM, CompM2, and CompM4 should have all warranted at least alteration numbers.  If the M68 were simply given new alterations, it would be slightly more difficult, as you would have to do more work (i.e. negotiate death-by-PowerPoint ad nauseum to get an alteration approved, a process that would take way too long and be completely inefficient due to bureaucratic messiness), but it would require less than giving it a brand new designation.

Optics and nomenclature are an interesting thing, namely because of their almost complete and total lack of consistency, as they seem to be based almost entirely on "who used it first?" -

The M68 is type classified using Army (or Ordnance) "M" nomenclature.  Hypothetically speaking, a change to the base model should be designated with an "A1," ect.  The CompM could be the M68, the CompM2 be the M68A1, and the CompM4 be the M68A2.  

On the other hand, the TA31RCO uses the "Joint" nomenclature, using the "AN" prefix.  Alterations to Joint items are designated with sequential letters, e.g. "AN/PAQ-4, AN/PAQ-4A, AN/PAQ-4B, AN/PAQ-4C."  However, the Army, after using the AN/PVQ-31B for a couple of years ended up asking for their own version, which was again granted an Ordnance number, "M150."  

SOPMOD Increment 2 accessories, on the other hand, appear to follow none of the "common" conventions (Army, or Ordnance, Joint, or Navy), instead preferring simultaneously more logical, but quizzically almost more confusing prefixes like "SU" for "Sight Unit," and "LA" for "Laser Aimer(ing)."  However, some Increment 1 items used Joint classifications, e.g. AN/PEQ-2, AN/PEQ-5, ect.  Furthermore, they seem to add, almost at random, resembling Joint classifications and even alteration conventions, but added as a suffix behind a slash, with alterations separated by a hyphen, resulting in things like:  

SU-230/PVS-C

On top of that is the difference between numbered and type-classified systems and systems that are just "generically" classified:  

"ACO" is certainly what the TA31F was "called," but it was not type classified with a specifically numbered designation until the AN/PVQ-31A and B.  

Similar is the 4x Day Optical Sight (DOS) and Enhanced Combat Optical Sight - Navy (ECOS-N).  Classified and designated... but not...  

...superseded by SU designated items.    

Of course... we haven't even gotten into Air Force nomenclature... thankfully they don't mess with small arms too much, and except for the GUU-5/P situation, pretty much just use everyone else's designations for things.  

Then of course is the whole "M45" business and "CQBP" deal... where the Marine Corps "invents" an Ordnance (Army) designation, non-sequentially numbered, based on an "abbreviation" of a non-doctrinal, and at the time, no longer applicable name - "MEU(SOC) .45," generated by the popularity of referring to pistols by caliber rather than designation... probably going to be superseded by a similarly fuzzily named "CQBP" that *will not* be an "M45" because... oh brother.  

Unfucking this all would be a paperwork nightmare, and many an OER would suffer miserably, and many late nights sustained by coffee and cigarettes would be spent in front of a CAC enabled terminal re-learning gradients for text boxes.  One that no one in their right mind would even begin to suggest trying.  

In other words - we've bureaucratically crippled ourselves to the point where we can't even follow our own rules.  

The not so short moral.*

~Augee


* I'd like to state at this point as a disclaimer - I am well aware that there are FAR more important things for the military to be worried about than getting and/or straightening the minutiae of nomenclature out - and I am not suggesting that it should, or needs to happen, nor am I implying that anyone involved in this process somehow failed in their duties.  

My comments are derived from an interest in the history military technology, of which nomenclature is a part, mixed with some playful ribbing brought on by an obsessive compulsive personality disorder poking fun at a career path has forced me to become familiar with such things.  

AFAIK, Block II uppers are referred to as 10.3" RIS II URG (Upper Receiver Group) and 14.5" RIS II URG (Upper Receiver Group).
Dustin

Thanks for the info Augee.

Is this a "common name" or have you seen them classified as such?  

I've seen them referred to colloquially as such, but never as an "official classification."  

I also have what I assume to be a military surplus upper receiver that's marked with an IUID that lists it as a "barrel assembly."  

Also, there have been a couple of CQBRs photographed with small... "buttons" or markings on or near the cam pin "hump" that may be some sort of identification marking.:



It would be interesting to scan one of these and see what the IUID reads out.

~Augee

That muzzle seems photoshopped to me for some reason

pic thread

It is from documentation.
Dustin

Well, there you have it.  

Did the documentation say whether or not new NSNs had been issued for the URG as an assembly?  

~Augee

They issued you a URX with a fixed FSP?

Surely hes talking about the M4/M5 RAS, not URX.  Replacing a URX with aDD  RIS II is a step backwards, IMO.

Does anybody know which Pelican case SEALs have their MK18's in? I've seen a couple of pictures of SEAL cases with an M4A1 and a MK18 receiver too.

It is a URX...see below

Dunno why i didnt catch that, i responded to his pic already.  Im jealous, my 3 letter agency just got away from Colt SMGs with fixed carry handles...

Finally almost finished..been building/waiting since feb for this.
10.5 LMT Upper with DD MK18 Rail
Engage Armament SBR lower
Geissele S3G trigger
Magpul STR Stock/ Also have an LMT SOPMOD for it
Magpul ASAP
Magpul BAD lever
Troy buis
BCM bcg
Battle Comp
Going to order an Exps 2 for it, or throw my aimpoint comp m4/3x mag on it.
Cerakoted Burnt Bronze by Bollinger's Gunsmithing in maryland(Highly highly recommend them, awesome work they have done a few rifles for me)

http://i122.photobucket.com/albums/o280/ajring/2012-10-29_13-49-21_669.jpg
http://i122.photobucket.com/albums/o280/ajring/sbr1.jpg

My SOPMOD MK-18 clone!

Well done.

EXPS3, AFG, and looks like a streamlight light....interesting

I think it's an X300 pistol model.

Gonna beat Augee to it.  

Note the tear drop FA.

Yes it is a Surefire X300

MK18 guru's........

I need your help on my MK18 build.  Come over to my thread and help me out!

Finally got to pick up my surefire 212 monster suppressor today. Here is a cell phone pic I snapped while I was giving it a test fire on my mk18.

What barrel length is that, 10.3" or 10.5"?

What mount are you using.....the SF brake or the flash hider?

Come on dude, it'll work.

Take it easy on us Ohioans. We're a little slow.  

Dude, you gotta understand...... I needed confirmation.  I was concerned.  I don't sleep until I have it all planned out.



But after you showing me that video of Vickers using the SF on his DD MK18......I am so happy.  I just need to find a damned upper.

That is the 10.3" DD barrel using the sf 212 hider mount. It's a close fit but not a problem at all. I'll try to take some better pics this weekend to show the amount of clearance.

About to pick up a DD MK18 upper, and am deciding between a Noveske gen 1 lower, or a Mega billet 3s lower to pair with it.

I obviously can't easily find a DD lower to pair the upper with...as they haven't offered lowers individually for quite some time.

Any experiences with which lower between the gen 1 Noveske and Mega billet 3s pairs up best fit and finish wise with a DD upper?

A billet lower wouldn't be kosher

Yeah. I'm honestly pondering just picking up a new complete DD, and just selling off the upper. It may be the easiest option considering I strongly prefer matching my uppers and lowers, and likely won't take much of a hit selling the factory new DD upper to keep the lower.

CQBR project:

My NT4 finally transferred to my SOT a couple of weeks ago.
This pic was taken at his shop during visitation hours, the wait begins...

Looking good Brother..You gonna make the clone shoot in December?

I was planning on it until Neil posted the date on my youngest son's birthday.
To bad, the weather should be a "little" cooler than the SPR shoot we all participated in...

What groups can I expect from a mk18 10.3 DD barrel using 55gr fmj and 69 smk?

There was a member here about 6 years ago that posted a 600yd test result with a 10.5" LMT upper and ACOG, and was able to keep all shots within roughly 12 inches if I recall correctly.  Dont remember ammo used, probably had a 77 gr SMK since that was the craze back then.

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