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).

----------

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.

----------

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

----------

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

----------

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).

----------

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)

----------

Link to previous threads

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

Going through my parts stash for a grip and found two A2 grips, but one of them has a bit of a palm swell. No idea who made it, but it feels pretty comfortable. Anyone ever seen one like that before?

Lonestar?

Not my pic:

nvm.

Yea from description probably a lonestar

Been meaning to take a pic of how I pack my Pelican.

Ok

 

Nice setup - I'm on the fence deciding foam or no foam for a new 1700...  No foam obviously gets you way more storage, but just have to get over the "protect my babies" mindset :).  I"ll probably do foam for the MK12 and maybe one with no foam like yours for the MK18 and other SBR, plus related stuff maybe

Nope. I'll try to get a comparison pic tonight.

If anybody's looking for a Surefire SOCOM 556-RC (not RC2), Silencer Shop looks like they have some in.  Bad news is they are black, but nothing a little ceracoat can't fix.  Also look to be about full price.  Over $1200 in my AO with "Powered By".  I left them for you guys as I am set.

Just in time to beat 41f.......

damn it... I have a Surefire SOCOM-SB but kinda want an RC... although I see they have the Mini-4's in stock again, which is probably by far one of my favorite suppressors... I think ive just really grown to like mini cans across the board.

tempting...

Meh, no foam.

I use the TinyCrumb method:  just throw 'em in there.

Thanks!

• Although it's not shown here, I don't entirely go "no foam". I keep the top foam in the lid and it's what keeps everything in place when it's closed.

• Having just one piece of foam isn't optimal, mostly because it throws the weight distribution off so when the case is standing on its edge it falls over a lot because all the weight is in the bottom of the case. But the stock pieces of foam that come with the 1700 are super thick - totally unnecessarily so. A more optimal approach would be to order just 2 thin 1/4" sheets and put one on top and one on bottom. I've just been too lazy to order them but probably will soon.

• Either way, whether you put any foam in there or not, I'd definitely get over the "baby it" mentality. If your clones are built properly, they're military-quality firearms that go through more abuse in a day of service in the sandbox than a lifetime in a pelican case. They'll survive. Using this setup with either no foam or just the top foam, I've never had anything damaged and have never lost zero on any of my optics. You can also protect individual items that are more fragile by just throwing them in an individual case. I.e., when I through my NODS in there, I have a little canvas case that they fit in to prevent any scratching/abuse.

• Another bit of advice is that I normally pack this exactly opposite of how the pic is shown, so that when the case is closed and handle is up, the rifles are in their correct orientation and not upside down. If I packed it like the photo, all the weight of everything would be coming down on the optic, whereas in the reverse, it keeps the scope at the top with no weight on it. Probably unnecessary for range trips or whatever, but a good thing to do for flights.

This is how I packed to beat the weight requirements to fly to Texas for the weekend last year.

- Two full rifles

- Two Suppressors

- VP9

- NODs with helmet

- Shoes/clothes

- Med Kit & Cleaning supplies

- Some mags

If this kicks had some tread on them they wouldn't fit!! I envy all contents of that box... Except the shoes and spare clothes

This case seems to lack wheels. What do you do, carry it like a peasant?

C'mon now.............we all know he has a Chai boy for that.

" />

Here's the one I've got. No markings, so who knows where it came from.

Wow that is a cool build.

I must have MK18 FSP.

anyone know of a source besides SAW for Colt 10.3 CQB 5.56 Barrel ???

Those of you running a Daniel defense 10.3 barrel suppressed, what buffer are you running?

ST-T2 with std carbine spring, suppressed & non-suppressed, commercial 10.3 (large gas port) & .mil overrun barrels. They work just fine for me with all varieties of ammunition.

Deleted by moderator. Links to this site and or vendor are not allowed on this site.
 

I have a couple like that.
I'll have to see if I can find them and look for markings.

Thanks. It's in desperate need of an anodized G33's though, lol.

I always thought the 553 was the coolest looking eotech on pretty much any clone build... I didn't like returning mine but was tired of sending it back to EoTech for reticle fading about once a year. I know that's pretty infrequent, but a huge pain given that I never have send back my aimpoints. sick build...

EDIT: Oops page ownage. old pic... always thought this dudes mounting choice was interesting... makes those Wilcox NVG risers look like low pro mounts

I am running a H2 in one of the military overrun DD barrels with the smaller gas port. I would probably recommend a H3 in the commercial version.

H3+BLUE.

Both Mod 0 and 1, H2 + Red. Suppressed and unsuppresed they're an absolute peach to shoot.

Although I only ran mine suppressed with a few variables that would influence the reliabiltiy and function and only about 100 or 200 rounds, I would have to second sbye on this. I have an H2 in mine and I believe it would be less violent with the H3.

I think that's a perfect example of "who cares what it looks like, do what works best for you".

I run an H2 with a standard Colt action spring with a "commercial spec" DD barrel.  

~Augee

Why come your NT4 hated my stick so much?


Need a night range trip soon if you're willing good sir. finally got a sling.

BUT IT'S TOO HIGH!!  You'll get AIDS and SARS and miss everything you shoot at because CHIN WELD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!    pfffffffft   Heck, that's even higher than most carry handle set ups because of course the eotech reticle makes it higher than most carry handle mounted optics set ups.  

agree... if that dude is rocking head and body shots inside whatever standard they roll with... more power to him. honestly, I like higher optics and chin welds.... I do just fine with them and even like the rmr/doctor on top of an acog. just have to know your offsets I think.

You guys that did 80% lowers and had them anodized, did you have any clearance issues when you tried to install the lpk afterwards?

From what I've read (haven't done mine yet), Type III adds .001 to the surface. But I also read that US Anodizing reams the trigger pin holes to account for this before coating. I have not verified this, so you may want to contact them and ask.

Copy that, thanks SS.

Also, if I want to do a MK18 Mod 0, the engraving would be a M16A1 marking, correct?  I swear the VBSS MK18's I used were M4 marked but I honestly can't remember.

Page 1 says A1 lower.

Not mine, but a Gen 1 LMT with buffer, tube and spring.

https://www.ar15.com/forums/t_7_119/1558088_LMT_GEN_1_SOPMOD_STOCK_WITH_LMT_BUFFER_TUBE___200_SHIPPED_.html

 
Yeah optics is what I was thinking, but it's aimponts so they should be no issue as i think on it.  Will try it out this weekend, have to look around to see if I can find some skinny foam :).

I was pretty much a nay sayer on the Wilcox Risers and rising the optics already more than they needed to go, until I shot a riser setup under NODs in that class.

While you can checkweld with NODs, it's just as easy to not and simply use the buttstock as just something to support the recoil against your chest/shoulder.

Nice name, dude. Before I forgot the password, my last accounts username was Revolver Ocelot.

Anyway, any of you WV/MD/PA guys want to get a shoot together? I've got a set of Sentinels coming next week, and I can't wait to try them out. All the damn ranges around me close retardedly early. Peacemaker National being a prime example. Still need a helmet, but I'll be ordering one soon.

And something a little more on topic:

Took the light/laser off my Glock to see if something similar to it would make for a good ambidextrous setup. It's actually not terrible.  

" />

Not very clone correct, but I'm really digging this switch setup:

" />

Lots of Mk 18 Mod 0s were built with M4 lowers too. You're not remembering incorrectly.

It's funny how many MGS fans don't even get the reference.  I was a huge fan of that series; I still need to pick up V.

Oh and nice rifle!

Ah, good to know.  Thanks for confirming, TC.

I recently started using this configuration and am pretty pleased with it.

H2 and blue for me

 

" />

Bitch is clean...