DD MK12 SPR 5.56 NATO 77 gr. SMK QL/Node/OBT Help

[Alaska]

.............I have the Leupold TS30 scope and zero with the MK262 Scope Dials starting at 100 yards.

Check your bullet holes at 100 yards......sometimes that will tell you if your stabilized. If your using a 1-7 twist you should be fine.

On the Mod 0 I used ARMS #40 low profile SP rear sight
I could not find a KIght Full length SPR rail so I went with the PRI SPR full rail......which looks identical.

Once the MK 12 is dialed in ........takes the fun out of it........hitting is easy.
My MK 12 is the most accurate AR I have ever shot........even after 26 years in the Army.

The MK 12 SPR program has been
phased out ........crane has stopped making them. This was one bad ass AR. That is why I made one

 

[longrangehunter]

Jeff,

I'm sure they're being stabilized since Daniel Defense uses a 1:7" twist. It's just I've had AR's that have shot better 100 yard groups, one shot dime sized groups but would go wild out at 300+ yards, yet it had a fast twist barrel. I don't remember the twist rate but it was when Bushmaster first brought out their Varminter Rifle back in 2003.

So far the gun has been showing decent hits on steel out to 300 yards. I decided to send back the LMT DMR stock and I will install the Magpul UBR stock I bought to replace the factory DD stock I'm not thrilled with.

I got out the Noveske Afghan, mounted a Trijicon ACOG TA31RCO-M150CP w/a Green reticle and a LaRue QD mount and test fired it. Works very well with either both eyes open or closed on longer shots. I like it, one day in the bright sun and snow it was a little too bright, and I had to hold my left hand over the fiber optic tube to reduce the brightness of the reticle in the field out at almost 200 yards. I'm sure most of you guys in the Military that had issued M4's and 16, used these scopes if they were fitted with optics? Very small compact optics, super bright and clear. Top shelf optics for a battle gun.

 

[Alaska]

I used the Aimpoint and still have it but mounted it on my SCAR here at home.
At 300 yards I am shooting soda cans with my MK 12 with 855 ammo.
Yes we used the ACOG and Aimpoint.........I preferred the Aimpoint for scepicity.

As for stock best results is always with a rifle length buffer spring and buffer system are very good with rifle length gas system on the MK 12.
I have a A2 stock........I currently have the Vltor EMOD A5 system with Tubbs Flat wire buffer spring and works great on it.
I also have a LMT SOPMOD stock with H6 buffer and a Tactical Spring.com buffer CS spring that works great.

My upper was Colt Match Target so I had M4 Feed ramps cut for it .......very smooth feeding from the mag to chamber.

Just remember a slow carrier/bolt is a happy AR
........avoids carrier/bolt bounce.

My carrier I am using a M16 carrier that I had WMD put their NB finish on it.
On the Bolt
I replaced the bolt with a Sharps Reliable Bolt.
I replaced the extractor spring with a 5 coil and black insert buffer (no donut ring or D ring)
I replaced the 3 gas rings with a 1 piece gas ring McFarland.
Replaced the ejector spring with a CS one from Tactical Springs.com.
Replaced the Firing Pin with a Titanium firing pin.
On the Carrier
Replaced the Cam Pin with a POF Roller Cam Pin kit................very nice.

Some of these modifications were done to the MK 18 so I used them on my MK 12.

 

[longrangehunter]

Here's a photo of the DD MK12 with the Magpul UBR Stock installed. I really like this stock, very solid, no movement on the check weld mounted to the receiver extension tube, allows the shooter for nose to charge handle or further away and still have your face on the check piece, lots of positions that can be altered through preset(s) and/or the check piece itself. I will more then likely remove the side trap door (it comes with short screws for this purpose). Nice piece of equipment, A+ IMO.

 

[Alaska]

Another good load

IMR 8208 @ 23.8
77 MK
LC Brass and CCI 41 primer

2.245" COAL

 

[longrangehunter]

So it's been a while since I got out to shoot the MK12, and the load I developed using RL-15 and the 77 gr. SMK. Yesterday I started out at 347 yards using a tripod and a Hog Saddle. The grass is very high here...... well over 3' , so I sat on the berm of the No-Name Creek and made two solid hits with the first two rounds. I was using the data off my Shooter App even though the USO 1-8x27 has a custom BDC reticle for the 77 SMK. The App called for 1.5 mils.

The scope is very close to the Shooter App, but I remembered I hadn't used the proper zero in the reticle, which is 1/2 Mil down from the center dot, and has it's own red dot when lit (shows for a 50 yard zero). I basically just used the Mil hash marks to get on target.

Next up was a 19" round steel target at 620 uphill at 9 degrees. I shot this prone off my backpack with the bipod out and off the end of the top of my backpack. Sure enough the App was very close calling for 5 mils, the round hit right in front of the steel. The next round made contact holding near the top of the steel. I then let a dozen rounds fly and put 10 rounds into the steel only missing the first round, and two others within the string. Not bad I thought since I was just tossing the rounds out there, either way the gun does produce acceptable accuracy for a DMR.

So this is the gun I plan on using in a team event down in MN at the Steel Safari in October of this year. I've never shot an AR at any event so this will be new for me, but I have shot at the Blue Steel Ranch before. Hopefully after I get the gun dialed in with the BDC reticle I won't have to rely too much on running the App for all the dope, but I'll have to wait and see how that turns out?

Good gun considering the 77 gr. SMK dropped 115" or so to make that 620 yard shot, and near the outer limits of the 5.56 NATO round.