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

Hey guys , I've tried to contact the source of the DOD stickers,
But no luck. Do any of you have 4 or 5 you would like to sell?
Shout me a e mail if you do. , thanks. Aaron

And Navy Combat Camera. That is who you see in AOR2.

Don't have any personally but if someone has a decent image of one I can recreate it in an art file that can be used for printing.

I also had no response. A generous member offered to put some together and we found the art that Augee posted a while back; however, I haven heard any updates. I am not a patient man; therefore, I ordered some back-ups from PX Airsoft ( or something like that) in Hong Kong. They took PayPal, so I figured it was safe enough. They are definitely not as clone correct as Augee's art, but if they come in before our fellow team member can get some made, I'll post some pictures.

I would gladly chip in for some as well.  I also tried contacting that source and got blown off as well.

I asked him where he has been and that some in here are looking for stickers.

His response to me yesterday.

Cool, thanks,  forgot about it being the Holliday season,

How does he run the blast shield and the surefire can? The Ferfrans blast shield doesn't work with a surefire brake does it?

He swapped them out.

I just got around to cleaning my CBQR after a few thousand rounds suppressed..

Deleting some of the thousands of pics off my phone and I noticed this.  Don't remember seeing it before in here but may be wrong

No pics?!

Is there a specific colt upper receiver that is GTG?  Certain Markings "C" etc. or ia any flat top colt upper receiver GTG?  I have a complete DD MK18 upper I plan to replace the upper receiver to get rid of the DD white markings.  

So I think I'm done I may change the stock and grip but I like the set up.

M4A1 Colt
DD 10.3 BBL
DD MK12 GB
DD RIS II RAIL
YHM 3200 QD Can (I machines off the glass cutter on the FH)
Surefire M300 Scout
PEQ - 15 Real Deal (I have 2 additional units available)
Surefire Dual Switch
KAC VFG (I like them)
KAC Sling Mount
KAC Front BUIS (Rear in bound)
Matech 600 Rear BUIS
EXPS 3-0
Vcas Sling

I did use the new Magpul Furniture though, I do believe that I have seen all of these in pics used in the field.

STR Stock
Moe K Grip

I just like the way they feel.



Here are few shots of the new look to the YHM FH QD.... I hated the glass breaker shit.

I don't know if there are any other Colt M4 upper receivers besides the one.  It will have the "C" stamped on it. I did the same thing though, swapped out the DD white marked upper for a Colt.

Gotcha and M4 stamped on the front of the flat top rail where it mates to the RIS II right?

 

Just left Capitol armory with my new can!

Bringing something else home to make your wife less mad? Congrats the rig looks awesome!

Looks like a good day, a box of 223, a new can, and a purse.

LOL. Good eye. I didn't even see the purse bag

You can almost always tell how many firearms a man owns by how many Coach purses his wife has.

Let's just say that my wife has a ton of Coach purses.

We get off pretty easy considering. Her Coach bags are far cheaper than any of my rifles, and cheaper than most of my optics as well.

 

I want mine bad.

My wife prefers guns to overpriced status symbols.  

Oh, my wife has two LV bags.

She has like two dozen Coach bags though.

correct

I wish... my wife is a shooter.

Her Christmas was an EoTech XPS-3 for her SBR and an HK45 CT.

Also a recurve, because she wants to get into bow hunting.

Q: What's the quickest way at first glance to tell the difference between a mil and civi Block II?

A: Ladders on every spare inch of rail.



ETA: Pic thread:

Ya I was pretty excited about this one
I got a PAC timer for Christmas so I plan on dojng a lot of drills tomorrow.

Those pics were taken in CA at Burro canyon, the instructors are with TFTT/DAG. there was also a video posted a few times in this thread of them instructing cqb/breach/clear to non-"high speed" types at the same range.

Yeah it's somewhat old. Might have even been posted in the old MK18 thread.

I'd rather keep my ladders, shooting on a bare rail without gloves is painful.

If you've got girl hands

It's not bad this time of the year, they keep my hands warm, but in the summer I have to but on TD rail covers. The ladder ones are useless.

So my dad bought a QR code maker. He made me my own personal label. Pretty cool. Is 3W544 the correct Cage code for LMT?

Nice! Not sure if the code is correct or not, but I need one.

It's pretty cool. I'm gonna head over there on the weekend and see if I can make one for my MK25 too.

My wife has two.  Yes I bought them.

Obviously, I got off easy.  

She gave up bitching about guns and ammo forts a long time ago

Awesome! Yeah, 3W544 LMT's Cage Code.

Just a small note - the marking on the stickers aren't QR codes, they're data matrices.  Just for anyone that pays attention to that kind of thing.

1230141850 by 4DAIVIPAI2K5, on Flickr

1230141846a-1 by 4DAIVIPAI2K5, on Flickr

Can someone take a pic of their locking ring on their surefire can? Is it offset?
I can't get mine to lock on I just shot it and my can flew 15 yards. It has me worried what am I doing wrong

No pics but the locking ring is offset.
Hopefully no damage to the can?

Who makes the most correct & sells the CAG Code stickers here?

All this rubbing doesn't seem right, this was a brand new flash hider/ suppressor

I don't know if it matters, but where are the shims? Is the FH Rocketted on well?

I was under the impression that you didn't need to shim a 3P.  I don't have an RC yet but my other suppressor with a vortex style mount has similar marks.

You do. I remember a whole long discussion about it

After I purchased my SR25, I graduated from Coach/Michael Kors to Louis Vitton's and Gucci's for my wife..ng is

ETA: didn't see all the responses after I quoted this. Thing is, she really doesn't even ask or wants those purses, it's just my guilt kicking in cause she never asks how much I spend and when she does (wanting to buy me b-day presents etc), I alway just tell her a few hundred dollars..LOL