View Full Version : Mk18 mod 1 / CQBR build please advise
So I attempting to put together a Mk18 mod 1 that is as close as possible to the rifle that is in service. Mind you this is my first AR.. So far I have the following items:
Colt lt6720-R
DD Mk18 RIS II rail
Lmt fde sopmod stock
Black A2 pistol grip
Kac taupe front flip up sight
Kac 200-600m buis
Kac combat trigger guard
Cqd sling plate and sling
Tango down fore grip
Next on the list will be a colt 10.3 barrel and kac flash hider. Besides optics, lights, and lasers is there anything that I need to consider changing or modifying? I belive that the colt low profile gas block
NoveskeFan
03-19-12, 15:43
Might be a dumb question, but, you do already have your NFA tax stamp?
No offense, but this is a quantum leap for a first AR. Many people say that your first rifle should not be a SBR.
Other than that, your parts list seems to be in order for a clone that is very up to spec.
Taxes stamp is in the works. Plan to set up a trust in a few weeks and submit my form 1. I have read the different opinions on here as far as the SBR being a first, I'm not to worried. The rifle has a 16 inch barrel that I can shoot till my form clears. The build is a tall order and is costing me a lot. I think it's worth the money and the trouble.
RKB Armory
03-19-12, 18:08
Unless you are dead-set on an exact clone, I would consider an upper receiver group that is already built. Daniel Defense sells a nice 10.3 inch Mk 18 URG. Let the experts build it for you.
If you are insistent on sticking with Colt parts for authenticity, SAW has complete factory Colt Mk18 Mod 0 uppers (http://www.specializedarmament.com/products/Upper_Receiver_Group_MK18-954-283.html). You can just shave the FSB and install the RIS II and not muck with the gas ports.
Arguably you can substitute a Surefire/BE Meyers 215A for the KAC flash hider, as Surefire won the most recent SOCOM contract for suppressors. It isn't as short as the KAC flash hider though.
That said, Noveske and DD offer factory Mk18 uppers with the RIS II. The DD has a 10.3" barrel, whereas the Noveske is a 10.5" My Noveske Mk18 runs and runs and runs...
Reagans Rascals
03-19-12, 19:56
Need to get the Crane etching on the magwell.... and the KAC NT4 QDSS Suppressor
High Caliber Sales does really awesome MK18 clones... Crane, KAC, Colt, and LMT parts....
Unless you are dead-set on an exact clone, I would consider an upper receiver group that is already built. Daniel Defense sells a nice 10.3 inch Mk 18 URG. Let the experts build it for you.
Mine had extraction issues right out of the box, BCM extractor upgrade fixed it. If I were to do it again I'd have bought a Colt 10.3 upper and did the conversion myself.
Well I already have a base rifle and I'm trying to keep it as close as I can to the real navy issued ones. I'm a inspector in a machine shop so boring out the port hole at those tolorense is no problem. We hold tolorences + or - .001. Not to be rude but I was looking for suggestion to what I already have and if I missed any parts. I believe that the only thing I will be missing is a badger gas block. But my colt block is already a low profile one. I went with the colt lt6720 r because it would be cheaper then the specialized armerment rifle and has the proper roll marks. As far as engraving magwell that's a toss up. Haven't seen any military photos with it to justify doing it. Tuff choice cause I do like it. Again I'm not interested in off shoot uppers. Colt is the path i have chosen. Thanks for the many responses!
As for suppressor's I think Im going to go knights. Surefire looks like a nice option but no pics to confirm what they are going on. I believe AAC also got a contract. But not 100 percent sure if they are used on mk18's. Only thing I have read is navy seals got AAC cans on there new Hk45ct. Not so sure about rifles.
For the cost, I'd keep the 6720 as a mule upper (training, other uses) and pick up an SBR upper (and run it as a dedicated suppressed unit maybe - at least set it up around being a suppressed SBR capable setup).
A 6933 upper with a Centurion C4 Cutout rail would be my SBR upper of choice if you want to go pure Colt. You then have a quality lower, and two uppers. One 11.5" you can use with or without a can, a a training/portable/high round count/lightweight 6720 upper to use in the interim, and continue using.
If you want outright best can for part time on part time off, Surefire without a doubt. For a mostly suppressed upper, the AAC is the best value hands down, though an 11.5" opens up a full range (to a Titanium dedicated thread on, to an old school OPS Inc reflex can) For the money, though I'm not an AAC fan, it's incredibly hard to beat a 6933 and AAC 91t M4-2000.
RKB Armory
03-21-12, 02:00
I believe the real M4A1 CQBR uses a government profile barrel, not a lightweight barrel. Granted, the barrel is barely visible in the configuration of this rifle.
Swapping barrel for a colt 10.3 from saw. When stamp clears.
RKB Armory
03-21-12, 08:04
Good. That way you don't have to worry about enlarging the gas port.
Yeah and after doing some reading looks like it would be better to swap colt gas block for the badger ordinance block.
ClearedHot
03-22-12, 07:38
Mine had extraction issues right out of the box, BCM extractor upgrade fixed it. If I were to do it again I'd have bought a Colt 10.3 upper and did the conversion myself.
What kind of extractor spring/insert came with your DD MK18 URG? Did you add an O-ring from the BCM extractor upgrade kit?
Bacon Six Actual
04-07-12, 10:20
The spec gas block would be either a Daniel Defense or Badger Mk12 gas block. The gas port isn't correct from the factory either, it needs to be opened up to .070" if it's not already there, .062" will be under-gassed.
Thanks for the heads up. I didn't know the badger gas block needed to be opened up. Almost have everything ready minus block, barrel and tax stamp.... Now I got to sell all the colt talo editon parts.
Bacon Six Actual
04-07-12, 15:05
The Badger block and the DD block are both .750", but the finish on the interior of the part makes it too large to be a slip on solution, so you generally have to hit the Badger part with a drill press and a 3/4" bit. The DD part will usually only require some sandpaper to take the finish off.
The gas port on the barrel itself needs to be .070", the block only requires opening up the main channel to .750" so it fits on the barrel correctly. They're both set screw designs, not taper pins, so it's a good idea to find someone to do the work for you, I HIGHLY recommend High Caliber Sales. Alan Brown assembled thousands of these rifles while he worked at Crane. Going with an experienced smith that has experience with the platform you're trying to clone is going to pay dividends, if only for the peace of mind knowing that it was done right and will run like a raped ape.
My $.02, of course YMMV.
What kind of extractor spring/insert came with your DD MK18 URG? Did you add an O-ring from the BCM extractor upgrade kit?
Standard M4 extractor spring and insert came with it, I used the o-ring simply because I have about 10 of them laying around with only 2 springs and inserts left. Gotta use them up.
Thank you for the suggestion. I want to do the swap out of parts my self. But I think you are right. I'm going to send my upper out to high caliber sales to have the work done once my lower reciver is papered.
Does anyone know if the mk18 is stored by the navy in a pelican case or do they use a soft bag to transport the weapon? I have seen a few pictures with what looks like a black hard case.
Reagans Rascals
04-10-12, 09:30
Does anyone know if the mk18 is stored by the navy in a pelican case or do they use a soft bag to transport the weapon? I have seen a few pictures with what looks like a black hard case.
They don't use the pelican day to day... that is a mass transit case... like when deploying overseas for transporting the weapons in the 130...
I suppose that's probably the only time they would have them in a case. I would like to put my mk in something authentic when I travel with it. I would like to cut my foam nicer then what I have seen in pictures of military kits. From what I have seen they hack it all up.
Bacon Six Actual
04-10-12, 16:13
I suppose that's probably the only time they would have them in a case. I would like to put my mk in something authentic when I travel with it. I would like to cut my foam nicer then what I have seen in pictures of military kits. From what I have seen they hack it all up.
If you want authentic, buy a weapon rack and throw it in a truck. Seriously.
The reason they're hacked up is because we generally only give a shit that it works, the foam in a Hardigg case being pretty, or using the hard case to begin with rather than something else, is a non issue with most military guys. As long as it gets there and my shit isn't smashed all to hell, what do I care how it gets there? The rifle sure doesn't notice the difference between a nice cutout and a hacked up cutout.
Do you want this rifle to use hard, or to show off and look at?
I realize they don't give a shit. To them it's a tool. It's not just a tool to me. Its not cheap to build and has some collector appeal to me. The rack comment is really cute. In my state we cant have gun racks. I suppose to be really authentic I need a hummer!
Bacon Six Actual
04-10-12, 16:31
Honestly they get stuck in a weapons rack and thrown in the back of whatever truck is handy.
I'm talking about a standing weapons rack, like this:
http://uwr.spacesaver.com/DefaultFilePile/Public/UWR/CatalogContent1/UWR12MK16R34.jpg
You're building a clone of a military weapon, if you want every detail to "spec", then make the case look like someone who just wanted it to fit had at it. Ain't rocket surgery my friend. :no:
Thanks for clearing that up for me!
Honestly they get stuck in a weapons rack and thrown in the back of whatever truck is handy.
I'm talking about a standing weapons rack, like this:
http://uwr.spacesaver.com/DefaultFilePile/Public/UWR/CatalogContent1/UWR12MK16R34.jpg
You're building a clone of a military weapon, if you want every detail to "spec", then make the case look like someone who just wanted it to fit had at it. Ain't rocket surgery my friend. :no:
Those space savers dont save much space, and were a PITA to bolt together since they cant be chained. I miss the old racks.
Just received my upper back from Kevin at High Caliber Sales. Very reasonable price, good service and fast turn around time.
Correct me if I am wrong, the Mk18 mod0/1 has a AR-15 lower
Yes. With out getting to involved in to nomenclature. Military rifle lower or Colt model M4= AR15. I believe the also used M16 lowers as well but I could be wrong. Can any military guys here chime in on that?
Yup, meanwhile the military issued I saw from this thread has the laser etched
http://imageshack.us/photo/my-images/160/mk18mod01zv4.jpg/
Yes. With out getting to involved in to nomenclature. Military rifle lower or Colt model M4= AR15. I believe the also used M16 lowers as well but I could be wrong. Can any military guys here chime in on that?
Not all mk18 have that. Only the mod 0. I believe that the mod 1 went out as a kit with only the upper so those rifle wouldn't be engraved. Again some one with more knowledge can chime in.
yes, so technically anyone that has a Mod 0 replace with the Mod 1 upper will maintain the engraved lower :p
I don't know about the navy, but all army mk18 I seen both mod0 and mod1 did not have any different engraving that I noticed. Also block 2 guns can come complete or as uppers.
Our rear sights for the Mk18 were just regular matech's unless the operator chose to put their own on.
I chose not to engrave the crane markings. I couldn't validate that they were engraved on the block 2's.
Are you trying to build an exact collector grade clone or a working SBR that you can shoot?
A real Mod 1 uses a 10.3" barrel with a low pro Crane (Daniel Defense) or MK12 gas block. It does not use a Mod 0 barrel with a cut down front sight base. Buying a Mod 0 barrel from SAW would be a waste of a barrel.
A better solution would be to buy a DD 10.3" barrel with the correct low pro block already pinned on.
I have been unable to find a factory Colt barrel with the correct low pro gas block. Even me hasn't been able to find one. So you can get it out of your head that you will find one.
A 6720 lower would also be incorrect for an exact clone. I would use a 6920 SOCOM lower that is correctly marked M4A1. MK18s are mostly built on M4A1s and some older M16A1 lowers.
Modifying the TALO LT6720R is the absolute most idiotic thing you can do right now. They are starting to bring $1700 to $2000.
I bought my Talo over a year ago and payed $1100 for it so I'm ok with the fact that I chose to modify it! I bought a Daniel defense barrel and low profile gas block. High caliber sales swapped the parts out for me. I happy with my set up and it's the closet build up that I have seen yet. My lower has the M4 roll marks.
Slightly off topic, but another big plus for the boys at High Caliber Sales. I asked them to do some pretty pain in the ass custom stuff - the finished product was exactly what I wanted and Kevin's customer service was some of the best I've seen in the industry. ...I really need to drop them a "thank you" :blink:
I'm sure your upper came out as well as what they did for me.
--David
Just received my upper back from Kevin at High Caliber Sales. Very reasonable price, good service and fast turn around time.
Pics?
Taxes stamp is in the works. Plan to set up a trust in a few weeks and submit my form 1. I have read the different opinions on here as far as the SBR being a first, I'm not to worried. The rifle has a 16 inch barrel that I can shoot till my form clears. The build is a tall order and is costing me a lot. I think it's worth the money and the trouble.
18196
Looks nice. I expected just a pic of the upper, since it sounds like you aren't approved yet. I'd be careful (avoid) about posting pics of the mated upper and lower if you're not approved by the BATF yet (unless the pictured lower is registered).
Looks nice. I expected just a pic of the upper, since it sounds like you aren't approved yet. I'd be careful (avoid) about posting pics of the mated upper and lower if you're not approved by the BATF yet (unless the pictured lower is registered).
Thank you. This thread is very old. 3/19/12 was the beginning of my post. My taxes stamp has been approved for over a year. I'm fully aware of the law and have done all that is required by the BATF.
That answers my qualifying statement above then, the lower in the pic is registered. You didn't call out the fact that you were 'updating' the thread and I didn't go back and analyze dates.
Just lookin out.
I have the MK18 bug now. I'm debating SBRing my 6920 and building/buying an upper or just buying a new 6920 and having the barrel cut, add the rail, and have proper gas block put on.
Does anyone know what ADCO charges for the second option? Being that 6920's can be found in the sub $1000 range it may be close to just buying an upper from say High Caliber Sales plus I get the lower too. I would also have all Colt internals per spec.
I am attracted to the pedigree of the guys at High Caliber Sales but is there any real "secret sauce" from a reliability stand point that I'm missing? Just cut the barrel, rethread, bore gas port to spec and add the proper gas block and extracter goodies...right? It's an AR not a 1911...or am I neglecting something.
I have the MK18 bug now. I'm debating SBRing my 6920 and building/buying an upper or just buying a new 6920 and having the barrel cut, add the rail, and have proper gas block put on.
Does anyone know what ADCO charges for the second option? Being that 6920's can be found in the sub $1000 range it may be close to just buying an upper from say High Caliber Sales plus I get the lower too. I would also have all Colt internals per spec.
I am attracted to the pedigree of the guys at High Caliber Sales but is there any real "secret sauce" from a reliability stand point that I'm missing? Just cut the barrel, rethread, bore gas port to spec and add the proper gas block and extracter goodies...right? It's an AR not a 1911...or am I neglecting something.
Adcoists their shop prices under "shop services."
Personally, I would sell the 16" barrel and get a Mk18 barrel from Ken Elmore at SAW. It will cost you, but it will be the closest thing to the real CQBR barrel you can get.
HCS uses, to the best of my knowledge, LMT uppers for their CQBR builds. LMT makes a good upper, but if you want a clone it will have the wrong barrel length and profile.
Adcoists their shop prices under "shop services."
Personally, I would sell the 16" barrel and get a Mk18 barrel from Ken Elmore at SAW. It will cost you, but it will be the closest thing to the real CQBR barrel you can get.
HCS uses, to the best of my knowledge, LMT uppers for their CQBR builds. LMT makes a good upper, but if you want a clone it will have the wrong barrel length and profile.
Why would buying a SAW barrel be more authentic than cutting down a Gov profile 6920 barrel? Isnt it just a regular M4 barrel with an extra 1.5"? Is there any difference between the cut down MOD 0 barrels and later premade Colt 10.3 MOD 1 barrels?
BTW, I had trouble pricing ADCO's services on their wesite. I only really saw barrel rethreading.
Why would buying a SAW barrel be more authentic than cutting down a Gov profile 6920 barrel? Isnt it just a regular M4 barrel with an extra 1.5"? Is there any difference between the cut down MOD 0 barrels and later premade Colt 10.3 MOD 1 barrels?
BTW, I had trouble pricing ADCO's services on their wesite. I only really saw barrel rethreading.
My understanding is that Ken at SAW cuts down 6920 barrels. He reparks them and opens up the gas port to the proper spec (this is important because he opens the port to the mil spec for use with full-powered NATO ammo, whereas many commercial manufacturers have larger gas ports to accommodate underpowered ammo that many people use (e.g., Wolf, Tula)).
The difference is that places like ADCO, which do a lot of good work, are general gunsmiths. Ken, on the other hand, works exclusively with Colt parts. He teaches Colt armorer's courses and I have heard reports (online, mind you) that Colt CS often directs people Ken's way for certain work in order to get a quicker turnaround time than the Colt factory can do.
This isn't to say that there aren't other qualified gunsmiths that can do the same work and maybe cheaper. I guess when it comes to Colt factory parts, I trust Ken to do the work over all others. It's pricey, no doubt, but peace of mind is worth something too (e.g., I want my 10.3 barrel to be 10.3, not 10.5 or thereabouts).
Ok, thanks for the insight. I'll have to think it through. I can't see how ADCO could mess up something so simple, but there may be some "secret sauce" I'm not aware of....after all the whole idea of a 10.3" AR seems sketchy but they seem to have been successful in making them run.
loganp0916
02-03-14, 11:37
BTW, I had trouble pricing ADCO's services on their wesite. I only really saw barrel rethreading.
From adco's site:
Standard Barrel Threading $65.00
This covers cutting/crowning as well as threading. This service is for any barrel not attached to a receiver/trunion or action. AR barrels with the FSB in place are covered under this service/fee. These threads will be the perfect size and will be concentric to the bore.
Sent from my iPhone using Tapatalk
Ok, thanks for the insight. I'll have to think it through. I can't see how ADCO could mess up something so simple, but there may be some "secret sauce" I'm not aware of....after all the whole idea of a 10.3" AR seems sketchy but they seem to have been successful in making them run.
That's fair. I will admit that there is some fanboyism in my response. I have used ADCO before and they do excellent work (if you want any specifics you just have to be very clear in your instructions). But I trust Ken more than others to have implicit and explicit knowledge about Colt weapons (including those that are issued).
davidjinks
02-05-14, 13:36
I will have to look through my old emails for the total price of the ADCO work order. I had them set me up my first MK18.
Build specs on that:
Colt LE6920 Upper
Cut, re-crown, phosphate barrel
Leave FSB in place
Add KAC Triple Tap
True up barrel threads (Concentricity)
One thing I needed to do after the original build was to have the gas port opened up to .071. I should've had them do .070 but I went off of LMT specs for their 10.5" uppers.
With an H buffer, prior to the GP work, it ran ok. Had several issues were the bolt would not lock open on an empty mag. I tried all known buffers from carbine to H3. It was hit and miss. After the GP work was done the bolt locked back on all empty mags with whatever buffer combination I put in it.
Accuracy was pretty good. With a 1-4X24 NF I was holding at 2" at 100 yards. With an Aimpoint T1 I was holding just about 3 inches. MK262 MOD 1 was is what I use for "go to" ammo. With M193 my groups opened up about 1-1.5" across the board. I make no claims to be HSLD uber shooter. So YMMV.
My second MK18 was done by HCS. Kevin built me a solid upper that runs. I did have an issue with zeroing my iron sights initially. With help from Kevin and Daniel Defense the issue was fixed 100%. Currently this upper is my HD setup. It gets run with a T1 in a LaRue 660 mount, Mini scout light in HSP mount. Lower is setup off a LE6920 with H3 buffer and SOPMOD stock. It runs off of all ammo I've tested it with including some really cheap weak .223 stuff.
When you say you left the FSB in place, did you shave it or did you make a MOD 0?
Are the MOD 1's all factory 10.3" barrels with LP gas blocks?
davidjinks
02-05-14, 16:57
First upper that was built by ADCO was a MK18 MOD 0. Second upper that was built by HCS was a MK18 MOD 1.
From my limited knowledge on issued .mil guns, I believe all MK18 MOD 1 rifles are 10.3" with LP gas block.
There is a technical discussion thread on the MK18 CQBR in Technical Discussion (I believe).
When you say you left the FSB in place, did you shave it or did you make a MOD 0?
Are the MOD 1's all factory 10.3" barrels with LP gas blocks?
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.