When discussing the Mk 18 / CQBR program, we can divide the history and discussion in to two distinct categories: 1) The weapon system itself / upper receiver supplied and 2) the group of accessories deployed on said weapon systems (SOPMOD).

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Mk 18 Mod 0 / CQBR

The M4 carbine and M16 are not ideally suited for all missions, so it was proposed that the modularity of the M16 series would allow a user to replace the upper receiver of an existing weapon with one more suitable to the task. One of two proposed special mission receivers that were planned for inclusion into the SOPMOD Block II kit, the CQBR has taken off on its own. Like the proposed Special Purpose Receiver, the Close Quarters Battle Receiver has been more or less taken on by the Naval Surface Warfare Center, Crane Division (often referred to as NSWC-Crane or just "Crane") as its own project following the CQBR's removal from the SOPMOD program. Just as the Special Purpose Receiver morphed into the Special Purpose Rifle, and was type-classified as Mk 12 Mod 0/1, the complete CQBR-equipped carbine has been type-classified as the Mk 18 Mod 0.

The purpose of the CQBR remains to provide operators with a weapon of submachine gun size, but firing a rifle cartridge, for scenarios such as VIP protection, urban warfare, and other close quarters battle (CQB) situations. The CQBR is designed to provide improvement over previous AR-15/M16-type weapons in this category. The CQBR is usually issued as a complete weapon system, and not just an upper receiver. The CQBR was once only available to Naval Special Warfare units, but the Mk 18 Mod 0 has become general issue for Visit, Board, Search, and Seizure (VBSS) missions and, as of 2006, for NCIS agents deploying to active combat zones.[citation needed] The Mk 18 is also used by the Coast Guard's Tactical Law Enforcement Teams, Maritime Safety and Security Teams, and Maritime Security Response Team and the United States Navy's Explosive Ordnance Disposal (EOD) Operators.

Wikipedia has a good article with sources on the original CQBR/Mk 18 Mod 0 and its development.

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SOPMOD

The SOPMOD Program Management Office at NSWC Crane, IN, provides standardized, versatile weapons accessories to meet needs across SOF mission scenarios. These accessories increase operator survivability and lethality by enhanced weapon performance, target acquisition, signature suppression, and fire control.

The CQBR itself was originally part of the SOPMOD program as an accessory replacement upper receiver for the M4. However it was eventually separated out into its own project.

SOPMOD accessories for the M4/CQBR originally included things like the KAC RIS/RAS, SOPMOD stock, KAC M4QD suppressor, AN/PEQ-2 illuminator/laser, ECOS-N red dot, ACOG, etc

The SOPMOD program has gone through multiple minor and major evolutions throughout its lifetime. The most significant is commonly defined as "Block II" and included the introduction/replacement of accessories that met the updated needs of operators. The most visually significant "Block II" accessory is probably the replacement of the KAC rail/FSB with the  Daniel Defense RIS II free float rail with low-profile gas block. Other updates include things like the Surefire SOCOM sound suppressor, EOTech RDS (553/SU-231 & EXPS 3-0/SU-231a), LA-5/PEQ ATPIAL, etc

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Link to docs and photo albums

 Presentation on CQBR from Crane
 Operator's Manual for Mk 18 Mod 0
 SOPMOD Program Overview presentation from Crane
 Photo Album of Mk 18 Mod 0
 Photo Album of CQBR with SOPMOD Block II accessories

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Because of the long history of both the CQBR/Mk 18 and SOPMOD programs, it's common to find weapons with various mixed configurations in the field, all depending on what time and unit the weapon system belongs to. Below are a few examples with descriptions to illustrate this.


Example of a Mk 18 Mod 0 in as-issued configuration including: M16A1 surplus lower receiver, SOPMOD buttstock, KAC RIS, KAC M4QD flash hider, Aimpoint Comp M2 in Wilcox mount, LMT rear fixed sight, CQD rear sling plate.


NSW Operator CQBRs with original SOPMOD accessories including KAC M4QD sound suppressor and AN/PEQ-2 IR Illuminator/Laser.


Member of a Combat Camera team with a CQBR with KAC RAS and M4QD flash hider but with other updated accessories from the "Block II" SOPMOD kit including SU-231a (EOTech EXPS 3-0), EOTech G33 Magnifier, LA-5/PEQ ATPIAL, Insight WMX-200.


Good example of "early" CQBR with SOPMOD Block II accessories including SU-231 (EOTech 553) and SU-233 (Insight M3x weaponlight).


Example of a more "modern" CQBR with SOPMOD Block II accessories including the updated SU-231a (EOTech EXPS 3-0) and Insight WMX-200 weaponlight.


Many times certain configurations are common within certain branches/groups. Here a Marine Raider is seen with a CQBR with an AN/PEQ-16 (USMC issued vs. the LA-5/PEQ SOCOM issued ATPIAL) and KAC NT4 suppressor (vs. the current Surefire SOCOM suppressor).

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Building a clone

If you're interested in building a "clone" of a Mk 18 or CQBR equipped M4A1, here is a basic parts list to use as a guide and get you started. This list is not exhaustive and see the * note above regarding personalized accessories.

                       | Mk 18 Mod 0                      | M4A1 CQBR Block I                   | M4A1 CQBR Block II                                      
Lower Receiver         | Mil-spec forged A1               | Mil-spec forged A2                  | Mil-spec forged A2                                      
Stock                  | Gen 1 SOPMOD (Black)             | M4, CAR, SOPMOD, CTR & others       | M4, CAR, SOPMOD, CTR & others                            
Pistol Grip            | A1                               | A2, ERGO & others                   | A2, ERGO & others                                        
Rear Sling Plate       | CQD                              | CQD                                 | CQD                                                      
Upper Receiver         | Mil-spec forged M4 profile       | Mil-spec forged M4 profile          | Mil-spec forged M4 profile                              
Barrel                 | 10.3"                            | 10.3"                               | 10.3"                                                    
Rail                   | KAC RIS                          | KAC RAS                             | DD Mk18 RIS II (FDE)                                    
Rear BUIS              | LMT Fixed                        | LMT Fixed, MATECH, & others         | MATECH, KAC 300m, & others                              
Front Sight            | A2 FSB                           | A2 FSB                              | KAC 99051 BUIS (Taupe)                                  
Front Sling Attachment | FSB Sling Swivel                 | FSB Sling Swivel                    | CQD                                                      
Muzzle Device          | KAC M4QD                         | KAC M4QD                            | SureFire FH-556-RC                                      
Supressor              | None                             | KAC QDSS NT4                        | SureFire SOCOM556-RC (FDE)                              
LAM                    | None                             | PEQ-2                               | LA-5                                                    
Weaponlight            | SureFire M962                    | SureFire M952, M962                 | Insight M3X (Tan), Insight WMX200 (Bronze)              
Optic                  | Aimpoint Comp M2 in Wilcox Mount | Aimpoint Comp M2 in QRP Mount, ACOG | EOTech 553 (Tan), EOTech EXPS3-0 (Tan), ELCAN 1-4x (FDE)

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Link to previous threads

 Previous Mk 18 / CQBR Thread Part I
 Previous Mk 18 / CQBR Thread Part II

Does anyone know when KAC might be doing another run of 99051-taupe sights? Seems they are out of stock everywhere.

Check your inbox

Ark Defense is the one stukas had. It's basically the same as the exos except the markings.

I only found one place sellin the ark defense ones and all they had was black in stock. Are they the originators of the ti-7?

lol I agree - just doesn't do it for me.  But neither do laundry bag paint jobs, but everybody seems to luuvv those  

It seems Ark defense changed to Exos
But yes that is the stock I used for 2 tours.

I'll agree there is a certain hint of poop mixed with orange juice vomit going on with the color there, but what did laundry bag paint jobs ever do to anyone? Except be awesome, that is! ;p

lol just not my thing I guess ;)

Curious, was looking at a (relatively) decent deal on a WMX200 recently, but it just boggles the mind how close these airsoft Element brand WMX200's are appearance wise - they even have the Insight logo - not sure how they get around that... Anyway not sure if right place to ask but is there any way to tell difference between these fake/airsoft WMX200's and the real deal?  The pics are so close I can find any difference, and would hate to spend the $$ and wind up with the airsoft w/o any recourse....

They do make other colors.  They call the 'coyote'' (orange juice vomit) one, dirka. Thought that was interesting. I personally love the length of a b5 or lmt fully collapsed (I'm short), but haven't been able to find a length on these. I think it looks so odd because all we ever see are b5 or lmt sopmods. The ti-7 definitely doesn't come to mind often when thinking sopmod. Surprised to see so many strong feelings against it. I prob should've used the black as an example.

Based on all of the images on the E auction site, the fake ones use a plug that looks like a simple headphone jack.

I’ve got one on a non CQBR and I like it.

Not gonna lie, can't look at it with the blade on, needs a stock to be real

Yes, it is

Attached File

^love the Kac FF ras!
Eta- I just received a used lt15-10" that reminds me of the ff ras, but not quite. Anyone seen the 9.5" FF ras on a mod1? Any pics? There may have been one a few pages back possibly

Eta- nope, car bean length too.

Legit.

Anyone know when KAC is going to release the new batch of carbine FF RAS rails?

Any idea where I can get the DD RIS Armorers tool and not the crappy one that bends?

I know there were discussions in the past re the larue FF 7" on some MK18's ITW, but it was a Unit Purchase iirc, not an issued deal.  Still, I wouldn't turn up my nose at a Mod 0 with a Larue or KAC FF rail - in fact I would prefer it if building another one.

Check page 433 and 813 for some pics and more discussion re Larue rail.

I had a 7" LT rail on my Mk18 on an early 05 deployment to Africa and again on my last gig to Iraq in 07.  Also had that rifle in responding to both the Indonesian Typhoon in 04 and Katrina in 05.

ETA:  The rails were unit purchases.

Yep i got an extra larue rail that I had on mine before I chopped up a RISII FSP for my mk18.  I love the look of the Larue's but now I have a KAC Carbine RAS that may well end up on a MK18 inspired build.

As for armorers wrench I have installed 2 DD lite rails and 2 DD RIS rails so I just stack 2 or 3 of the supplied "suicide" wrenches on top of eachother and go at it.

@2005army

Try emailing DD customer service. They sent me a more robust wrench. The ones that come with the rail are garbage.

LaRue has the LT15 7” FF on sale right now for $172.90 and the 9” for $191.10...if anyone is interested.

Thinking about grabbing the 7” for my Mod 0...always wanted the KAC FF on my Mod 0, but can’t ever find one, and when I do it cost me my first born...

KAC is doing a run of FF RAS carbine rails soon. Price will be $325-350 or so. Keep an eye on KAC dealers.

PSA for those of you who prefer Aimpoint over EOTech on your clone build... Aimpoint is offering a limited run of the Micro T-2 in tan.

Link to Article

Also, for HK 416 aficionados, Brownells is acquiring and importing *some* 416 and 417 related parts; though sadly, not any actual lowers (but 80%ers that they will machine on their own apparently)

Link to Article

!!!



Hopefully they won't be ridiculously expensive.

Thanks Brother!

CD

If you have an armorer's wrench with a spanner for castle nuts (not the three nub style), it should work nicely on the DD RIS II barrel nut. I use the spanner on my Tapco Intrafuse instead of a DD wrench and it fits perfectly.

The smile says it all.

Thank you, sir!

Not soon enough!

Thanks for the responses. About to peruse some past pages. I would still like to find one with a lt15 but without the fsb.

Larue has had their "version 1" stealth rails on sale for about a year now - I've been tempted to pickup a 7" in case I build another 0, and a 13.2 to replace my 14" (13.65 actual) Centurion - the Centurion is nice and light and a popular rail, but the proprietary attachments are annoying, especially the rail section for a VFG - it's not very solid at all.  Plus getting tired of having to use adapters for everything, just going back to QR's for everything I think. I'm beginning to realize all these new-fangled attachment options (mlok,kmr,cmr) are a solution for a problem most of us don't have...

That's cool info man, and thanks for your service too!

July. jk. idk..  when they have extra and feel like sending them to the civ market. pm me a kac part no and I can see if any are available though distribution or direct and get you a price..

Anyone have any recommendations for a riser that will work with pos arms levers? Would like one for use with my 553.

had a knights long riser but the eotech didn't lock down tight enough.

It sounds pretty ghetto, but layers of aluminum foil on the pic rail work well to tighten up the base of the old 553 so the ARMS will grip. It’s an old trick that works with undersized rails or worn mounts.

I was looking closer at this pic and realized he's running an Acog behind a t-1. That's only the second time I've ever seen that. On Miami swat there was a guy that ran an Acog behind an eotech I thin it was. Is this somewhat common out there? Just no pics? Or is this a very isolated? Or is it just a way to hold all your accessories during transport? Seems like one solution to illuminating a ta01 and magnifying a red dot at the same time while adding a bdc. I'm gonna have to run my su-237 behind my comp m2

The T-1 is offset.

Looks offset.

I think the Miami SWAT guys were running them before magnifiers were common and that's what they had in the inventory.

Attached File

Tryin to poo on my party?   Idk, going off the the height and angle it doesn't seem offset to me. It looks 'straight up' from the rail. If it were offset I would think it would appear to be a little lower, or at least show more of the top. It looks as though it's a side profile. As is it looks like it's co-witnessed to the Acog. My eyes can't see well in a blurry pic though. I'll have to zoom better.

eta- ok,ok, now i see it. I see the small "overlap" between it and the Acog. Thought I found somethin. I'm still gonna dedicate a cqbr with an Acog behind an m2. (If there is even enough rail space) why not have a magnifyer that just so happens to have a bdc. I guess the Acog does it all without the need for a red dot. I guess we can't all be trend setters.

One more edit- his sling appears to be set up for right handed manipulation yet the offset of the aimpoint would appear lefty? Is that how you see it? I suppose offset can go either way, it just seems more awkward. I'm sticking with co-witnessed, makes more (or less) sense. lol.

@Spooled

I have both the Knight's Armament Tri Mount Extended Rail (Riser) P/N: 98617 and the PRI "PRi AR15 / M16 Flattop Riser 3 Hole" (shorter version of the RECCE rail) and those both work well with my 553 and G23.  The PRI is also rather cheaper at $74 compared to $280 and it does work with a rear sight as well.  I'm running a KAC 300m with it.  Hope one of those fits your bill.

Thanks I'll look into those, probably the pri since knights risers are unobtainable it seems.

i have read the larue riser is good to go being properly spec rail but looking to spend less

What offset Scout mount is that?

Edit: Think I found it