DD MK18 10.3" with AAC M4-1000 [Archive]

SteveL

01-12-12, 21:09

I recently contacted DD by phone to ask if an M4-2000 would fit on the MK18 with a 51T Blackout. I was told that it would fit, but that shims may be needed when installing the Blackout to push it out a bit more for proper clearance. That was straight from the horse's mouth, or at least one of them. I didn't cross check with AAC.

Pappabear

01-14-12, 05:24

that looks cool. I like it. Mine don't fit so flush, it doesn't bother me, but I do like the look of yours.

Congrats

Turnkey11

01-14-12, 06:54

I didnt have any wrenches skinny enough to fit the flats on my mount, so I had to stack about an 1/8" shims to install it. My KAC can fits real nice too.

krichbaum

01-14-12, 12:42

I actually did not know if this combination would work. I found conflicting info and no proof either way, so it's kind of nice to see that it will work...because it does look kinda cool.

The mount has to be installed with the handguard off if not shims are used. Otherwise, there's no way to get to the wrench flats. And the handguard just *barely* slides over the mount to re-install it.

Mahk

01-27-12, 03:19

rob_s

01-27-12, 05:36

I would be careful with "shims". A couple of our local guys bought 10" Colts and some brand of cans (forget what cans they were) and both had to "shim" the mount to get it to work. Last time I saw one of them with the gun he was getting endcap strikes.

markm

01-27-12, 07:45

Would this setup work with a 762SDN6? I don't know if the .308 cans extend past the mount any further than the 5.56 cans and I'd like to go with that particular can so I can share it on my MK18 and my bolt gun.

Should be no different.

I would be careful with "shims". A couple of our local guys bought 10" Colts and some brand of cans (forget what cans they were) and both had to "shim" the mount to get it to work. Last time I saw one of them with the gun he was getting endcap strikes.

AAC's mounts come with shims now.... ever since they started making brakes/brakeouts. The shims are actually pretty good, so I'd suspect something else.

Were these guys running long bullets? Or XM193 quality of ammo?

One of the can gurus said that Colt wasn't known for having the most true barrel threading in the world.

bugeyes

01-27-12, 13:23

Was curious what is 'MK18' means under Daniel Defense?

Reagans Rascals

01-27-12, 18:49

Was curious what is 'MK18' means under Daniel Defense?

what?

MK, as in "Mark" is a specific setup identifier

http://en.wikipedia.org/wiki/Mark_(designation)

MK18 designates a 10.3'' barreled, gas impingement upper, the MOD1 designates the previous in addition to the RIS II rail.

bugeyes

01-27-12, 20:06

thanks Rascals...is that DD barrel (10.3) a good barrel to build?

Reagans Rascals

01-27-12, 21:27

thanks Rascals...is that DD barrel (10.3) a good barrel to build?

depending on your situation, and your adherence to the NFA laws, its a great setup.

You can purchase the MK18 Upper Receiver Group already assembled through Daniel Defense or Rainier Arms.

CGSteve

01-29-12, 14:37

Just in case any of you guys were curious about other suppressor options for the Mk18 Mod1 setup, I called SureFire to ask if their suppressors would work on a 10.3" barreled upper with a DD RIS II rail system and the rep I spoke said it would not, or that it would be cutting it extremely close.

JasonM

01-30-12, 10:50

CGSteve

01-30-12, 19:04

SF makes an extended mount specifically for this setup.

Thanks, I did not know that and he didn't mention that to me.

rob_s

01-30-12, 19:23

SF makes an extended mount specifically for this setup.

I've seen that before, but I'm not sure it was actually made for it, but made for another gun and just happens to work in this application. The end result is the same I guess. I can never remember which mount it is though. you remember the model #?

Magic_Salad0892

01-31-12, 03:50

One of the can gurus said that Colt wasn't known for having the most true barrel threading in the world.

I was under the impression they had some of the best?

Who said that, and who did they say had the best?

I'd assume Colt, KAC, Noveske, and Centurion.

I've heard of concentricity issues with LMT before.

Mahk

04-29-12, 14:34

I know this is an old post, but can we get those pictures back up? I need a reference.

krichbaum

04-29-12, 14:49

I know this is an old post, but can we get those pictures back up? I need a reference.

Oops. I had to change web hosts and lost everything on the old server, so the links to pictures are all screwed up. I'll try to get the pics back up when I can.

Mahk

04-29-12, 17:47

Oops. I had to change web hosts and lost everything on the old server, so the links to pictures are all screwed up. I'll try to get the pics back up when I can.

Thanks man.

krichbaum

04-29-12, 18:37

Fixed (for now).

Stangman

04-29-12, 19:15

edit.

hunt_ak

04-30-12, 01:14

I didnt have any wrenches skinny enough to fit the flats on my mount...
I'm curious how the OP installed the brake as well after reading your post. Does it come with a wrench for the teeth or something?

jwfuhrman

04-30-12, 11:30

he put the rail on AFTER the mount?

krichbaum

04-30-12, 18:41

he put the rail on AFTER the mount?

Yep. On this setup the mount has to be installed with the rail off. There is a fully enclosed section right at the front of the MK18 handguard, but it's just big enough to allow the mount to slip through when the rail installed.

RCO'B

07-15-12, 16:17

I'm running an SDN6 on a Mk18 and it has no problem clearing the rail. Then again, it's a Noveske 10.5 barrel vs DD 10.3.

Mahk

08-22-12, 14:56

AAC just put this photo up on their facebook:

K18 and 'N-6

https://sphotos-b.xx.fbcdn.net/hphotos-ash4/380501_476972515654952_505008537_n.jpg

Dude said it works fine with the Blackout/Brakeout and 10.3" barrel.

So, I guess I know what I'm doing with my next check. :D

RyanB

08-22-12, 15:00

I've seen that before, but I'm not sure it was actually made for it, but made for another gun and just happens to work in this application. The end result is the same I guess. I can never remember which mount it is though. you remember the model #?

My understanding is that it was made for the 416.

markm

08-22-12, 15:07

I was under the impression they had some of the best?

Who said that, and who did they say had the best?

I'd assume Colt, KAC, Noveske, and Centurion.

I've heard of concentricity issues with LMT before.

It was like... Major Malfunction or... one of those silencer dealer types... it was a reference in passing in some thread on silencertalk forums.

Mounting the can and giving it a visual is simple. It's very easy to see if your straight enough to shoot. I've only checked one barrel that made me nervous.... one of pappabears LMT barrels.

RyanB

08-22-12, 15:11

Colt is known for concentricity issues but it's considered a risk for POI shift rather than baffle strikes.

Magic_Salad0892

08-22-12, 15:57

Makes sense. I've SEEN a baffle strike with an LMT barrel.

Todd.K

08-22-12, 17:11

Dude said it works fine with the Blackout/Brakeout and 10.3" barrel.

It depends on the mount. Old style (non "deep well") FH, or the new Brakeout (with wrench flats at the back) should work.

JasonM

08-22-12, 21:55

AAC just put this photo up on their facebook:

Dude said it works fine with the Blackout/Brakeout and 10.3" barrel.

So, I guess I know what I'm doing with my next check. :D

That's my photo.

It works very well. Just need the right mount.

CoryCop25

08-22-12, 22:47

I don't know if this helps but with the 51 tooth Breakouts and 51 tooth Blackout that I have, if you can see the wrench flats in front of the end of the rail, the suppressor will fit.
I just built an 8 inch 300blk upper with a blackout and a new Troy 7.2" Beta rail and the suppressor fit perfectly!

VIP3R 237

08-22-12, 22:57

Makes sense. I've SEEN a baffle strike with an LMT barrel.

Shit thats scary. You'd think LMT would do better.

I've only checked one barrel that made me nervous.... one of pappabears LMT barrels.

ClearedHot

08-24-12, 02:07

How do the DD MK18's run with a can? Are they overgassed? Does anyone know what the exact gas port size is on those uppers?

Magic_Salad0892

08-24-12, 07:15

Shit thats scary. You'd think LMT would do better.

They usually do. I'm willing to bet that 99.999% of their barrels are great. But the one I saw that had the strike was awful. The round didn't hit just the endcap, it hit an actual BAFFLE. Suppressor was a Gemtech.

dudshep31

10-09-12, 14:06

Just an update...pic of how close the aac m4-2k is to the mk18 rail

http://i1139.photobucket.com/albums/n557/dudshep31/IMG_0196_zps14b73fb4.jpg

Pappabear

10-10-12, 01:53

Thats badass.

jesuvuah

10-10-12, 06:26

those pics make me jealous

nimdabew

10-10-12, 14:29

Just an update...pic of how close the aac m4-2k is to the mk18 rail

http://i1139.photobucket.com/albums/n557/dudshep31/IMG_0196_zps14b73fb4.jpg

That is a 10.3" right?

dudshep31

10-10-12, 14:57

Yes complete dd mk18 10.3 upper, AAC brake out with two shims used to time it

STAMarine

10-12-12, 12:53

Just an update...pic of how close the aac m4-2k is to the mk18 rail

http://i1139.photobucket.com/albums/n557/dudshep31/IMG_0196_zps14b73fb4.jpg

Whoa, does AAC offer FDE suppressors or did you just paint yours?

dudshep31

10-12-12, 13:39

No...just fresh krylon

markm

10-12-12, 13:44

No...just fresh krylon

That's the way to go.

dudshep31

10-12-12, 16:48

Here's a pic of the whole gun with suppressor attached

http://i1139.photobucket.com/albums/n557/dudshep31/IMG_0194_zps3ae6c843.jpg

ABNINF

10-13-12, 18:42

Question for the gurus.

I've got a MK18 and an SDN6 already paid for and waiting on my forms to come back. If two shims is what dudshep used, does that mean two shims will work with mine as well? Is it that simple? Or will the difference in lengths between the M42K and the SDN6 and the differing backpressures require something different? For knowledge's sake, is it consistent enough that if I had bought an M42K that the two shims would automatically work for it?

Also is using the shims to time a result of barrel lengths, can backpressures, or both?

dudshep31

10-13-12, 19:23

The shims were used to time the brake part of the muzzle device. I've used AAC brakes many times and every single time, I used two shims. Will yours take two? Good possibility but you won't know til you try it. Using two shims also helped with the rail clearance for the suppressor. The different lengths between the two suppressors shouldn't have anything to do with the suppressor, unless you're trying to get more rail clearance.

STAMarine

10-13-12, 20:07

Here's a pic of the whole gun with suppressor attached

http://i1139.photobucket.com/albums/n557/dudshep31/IMG_0194_zps3ae6c843.jpg

Very nice!