View Full Version : MK 12 MOD "DOC"

11 August 2015, 14:53
I have always liked the Mk12. I like the idea of a precision AR. There were some things that I did not like about it or just wanted to change. This project has taken about two years and I am still not finished. Here is what I came up with.

- Rainier Arms Upper (came as a Matched upper & lowers set)
- Noveske 1/7 twist 18" Rifle Length Gas, turned down under the hand guard, with a Switch-Block and black Cerakote
- AAC 51T Break
- Young Mfg National Match Bolt Carrier Group - Full Auto
- Vltor/BCM Charging Handle with Mod 4 (MEDIUM) Latch
- LaRue 12.0 Rail with Index Clips and AFG
- Harris Bipod with LaRue QD Mount
- Troy Front Sight
- KAC 600 M rear Sight
- LaRue SPR Mount
- Leupold VX-R Patrol 3-9x40

- Rainier Arms Lower (came as a Matched upper & lowers set)
- Stag Arms LPK
- LMT Ambi Selector
- Timney 3 lbs Single Stage Skeleton Trigger
- Egro Grip
- MagPul Trigger Guard
- Colt A1 Buttstock
- Troy M16A4 Sling Mount
- Moleskin on stock

Lots and lots of Spray Paint.

https://im1.shutterfly.com/media/47a5d630b3127cc9bb7bfe094bc000000010O00AcMWbZy0aOG IPbtxu/cC/f%3D0/ls%3D00108449631820150811201141739.JPG/ps%3D50/r%3D0/rx%3D720/ry%3D480/?tn=-1773801602

https://im1.shutterfly.com/media/47a5d630b3127cc9bb7bfec0ca3900000010O00AcMWbZy0aOG IPbtxu/cC/f%3D0/ls%3D00108449631820150811201203125.JPG/ps%3D50/r%3D0/rx%3D720/ry%3D480/?tn=1084823367

https://im1.shutterfly.com/media/47a5d630b3127cc9bb7bfe214be800000010O00AcMWbZy0aOG IPbtxu/cC/f%3D0/ls%3D00108449631820150811201130748.JPG/ps%3D50/r%3D0/rx%3D720/ry%3D480/?tn=-18484719

[B]Now for the long part, the WHY:

The entire rifle is based around the barrel. I wanted a Noveske Barrel, they are the best AR Barrels around for accuracy and longevity. That issue has been beat to death so that is all I will say about it. I did want a rifle length gas system because of how smooth they shoot with rifle buffer system. That posed a problem seeing how John hated that system. So, I had to get with Wes at MSTN to get the barrel that I wanted. As far as I can tell they are the only ones that I know of that have the Rifle Gas system Noveskes. I wanted a Switchblock because I plan on shooting both with and without the can. On all of my other ARs I don't used one but I figured that with this being a purely precision rifle it may help. Wes was great and I got the barrel exact barrel I wanted. I can't say enough good things about MSTN.

Some of the part are just because I had them or I like them. The Upper and Lower were a matched set I got that have no play what so ever. That was what I was looking for in those parts. I have had very good luck with Young Mfg BCGs on precision guns in the past so I stayed with them. I went with the LaRue rail because it is my favorite rail and I do not think that there is a better one out there. I have currently have 6 different LaRue rails and I have never had an issue with any that I have owned. I like single stage triggers on my ARs. For my precision shooting I like Timney the best. It feels the crispest and has the least amount of creep. I used a Stag LPK because I had one on my parts bin and that is what I use on most of my ARs. I replace all of the selectors and triggers so no issues there. I have ambi selectors on almost all of my ARs because I shoot both left and right handed, and my wife shoots left handed. I have BUIS on all of my ARs no matter the purpose, that is just the way I am.

I go back and forth with my cans. I mostly use the SND-6 but I have also tried my Mini4 and like that a lot. Not sure which one I am going to dedicate to this rifle.

I have the Leupold VX-R Patrol 3-9x40 on it right now. This scope was never going to be a permanent optic for this rifle. It went one about two years ago. To be honest I really like it on this rifle. The glass is very clear and the fire dot is truly daytime visible. I am going to get a different scope for it with more magnification but I still have not figured what I want to put on it.

Last but not least, the moleskin. I like texture on my face and it helps me get back to the same spot on the stock every time. I also got used it it on my stocks in Afghanistan so my facial hair would't be pulled on my stocks. I hated that.

How it Shoots:

I have 750 rounds through it. Most of the ammo is MK262 or Hornady 75 gr BTHP Match. I have fired some M855 just to see how it would do and to record my DOPE. With the Rifle Gas and the Rifle Buffer it is the smoothest AR I have ever shot. I love the feel. I have had no malfunctions to this date. I have done a 60 round fast fire as a reliability test and still not one issue came up. (I would not call it a pure mag dump as I was still keeping it on target and just trying hit a man size silhouette target at 100 meters. The longest I have had it out to is 300 meters. I need to find a longer range to get it out there. I want to get it out to at least 700 meters when I get some different glass on it.

As for groups I have had my best with MK262. I can't find my photos of my groups so I am not going to even say anything about them. Because I do not want to get into any type of conversation with the internet "trolls". [crazy] I do have them logged so PM me if you are interested.

Let me know if you have any questions.

11 August 2015, 18:18
She looks good. What other glass have you considered?

11 August 2015, 18:51
I want something more powerful to get out there. The new Nightforce 4-16x42 ATACR looks real good. But the two I have been really looking at are the Trijicon TR23-2G and the Bushnell HDMR with the Horus 59.

11 August 2015, 19:09
Looks nice, but since you were basing it around the barrel, you didn't think of using a WOA barrel instead? Or were you just dead set on utilizing a switch block?

11 August 2015, 21:26
Thanks. I have spent a lot of time getting it to where I want it.

I have had both and the Noveske ones are a little better. I had a Noveske and a WOA 16" Recce type upper and the Noveske had better longevity of accuracy.

11 August 2015, 21:32

I'd love to see the groups you're getting.

Let me know when you're done with the 12.5 middy test, if you want I'll get you one of these 16" rifle gas barrels. I know it's not a 18" Noveske, but I think the performance might be close.

11 August 2015, 21:40
I'll never shoot a barrel out within the timeframe that I actually keep a rifle in the safe.. having said that I have several barrels that are sub MOA with me shooting. I tool this barrel(rifle) to a range meet last year and they all accuracy just as good as me, using my handloads. I won't argue that Noveske was the cream of the crop but I jsut dont see it now... I spent half as much on my barrel as a Noveske branded as get just as good accuracy and it will last 90% of the users.

Note: I've gotten .38" groups @100 yards with this barrel which is made by AR Performance....

11 August 2015, 21:45
Funny I am going the exact opposite direction. Had a PRI MK12 Mod 0 on a lower built with all great parts but far from an true MK12 build. Just started to gather parts on a build that is as accurate as possible. That rifle looks really good with the paint job you did. I would also like to see what your getting out of it group wise.

11 August 2015, 21:45
I like how consistent the Noveske barrels are, over the long run. I shoot a lot and want the same accuracy on shot 1 and shot 20k. That is why the cost is more. But if you don't shoot that much then no need.

11 August 2015, 21:46
I will have to try and find the pics.....or I will just have to go shoot some more.;)

12 August 2015, 13:59
I like how consistent the Noveske barrels are, over the long run. I shoot a lot and want the same accuracy on shot 1 and shot 20k. That is why the cost is more. But if you don't shoot that much then no need.

Are Stainless Noveske's seeing 20K+ Rounds without accuracy dropping ?

12 August 2015, 14:07
I want something more powerful to get out there. The new Nightforce 4-16x42 ATACR looks real good. But the two I have been really looking at are the Trijicon TR23-2G and the Bushnell HDMR with the Horus 59.

I have one of their new ATACR 4-16s on my bolt gun. It is REALLY a nice optic. I'm still learning/memorizing the new reticule, and I'm a huge fan of the MLR 2.0, but so far I've started getting used to the new reticule much faster than I thought I would.

I run a 2.5-10x on my MK12 and don't really want more and it can get out to 600 easy and I've shot it out to 800. But if you're looking at something with more mag, I've been very impressed with the ATACR.

12 August 2015, 15:06
Are Stainless Noveske's seeing 20K+ Rounds without accuracy dropping ?

My last 18" SPR did. Had it for about 7 years and it was great. It was one of the original complete uppers that came with the LaRue rails and the Intermediate gas system. I used it with a carbine buffer system on my lower.