The MK12 Special Purpose Rifle has been around 20 plus years now give or take and has achieved an excellent reputation for accuracy and effectiveness. I won’t go over it’s history and development here except to say it was developed as a light weight sniper rifle for special operations forces. It’s use in the GWOT went on to prove it as an excellent variant of the infinitely adaptable AR15.
Since then civilian buyers have “build” copies and nearly perfect clones of the rifle. It’s been used arguably more in the civilian world than the military world at this point since it is now no longer officially used by the military. It’s proven to be an excellent precision AR15 in every way even if it is “dated” compared to the never ending marketing to selling us lighter and lighter and more and more Gucci new models and variants with debatable improvements.
One thing I have noticed about the MK12 when it comes up in discussion is the same old subject about its effective range when it comes to accuracy. A lot of people seem to think its a 600 yard gun. Of course other people who know better will shoot them further but that doesn’t seem to make much of a dent in the never ending opinions of online commenters. So once again I decided to demonstrate what it can do and push it to its extreme limits. This will be ongoing for the next few months. So let’s get started.
My first thought was to start this off with all the usual sand bags and rests and all the stuff to replicate shooting from a bench on a range to milk accuracy. Then I decided maybe it would be better if I shot the gun at long range just like it would have been used in the field, bipods and laying prone or across a pack. If I couldn’t get results from there for whatever reason I would use a bench , rest and bags.

Shooting from prone using the ATLAS bipod and no rear sand bag, I shot the rifle out to 900 yards. Target used was the official 1,000 BR target with scoring rings. I used this instead of a steel target so we would have something to actually measure by and to show results. Ammo used was the ammo developed for the SPR. The Black hills 5.56MM MK 262 ammo with 77gr. Sierra match king bullet. I cheated a bit with the optic by not using the optic issued with MK12s. In this case to better see the target and make as precise of shots as possible, I used a NightForce 5.5x-22x. This insured enough elevation as well as magnification for long range. I will be using this optic for the further testing or this series. In this first test we are looking at the MOD 1 version of the MK12. Using the KAC fore arm, a douglas barrel in 1/7 twist and the usual ops inc muzzle break. Lower is Colt with SSA trigger. Upper is Colt and Colt BCG with all the correct parts etc. Future articles will hopefully include the MOD 0.

I caught a perfect morning to do this initial testing. It was 65 degrees with no humidity and a 6 o’clock wind that wasn’t even 5mph. After fine tuning the zero, I fired 20 rounds for “record” on a fresh target.

Target above is for final record group. It wasn’t the first attempt as I needed some time to fine tune the zero and settle in after a little practice. Since I am trying to show what it can do at it’s best, I am not bothering to show you my warm up targets since they were not shot with final zero and MK262. It’s expensive so handloads stood in till I was ready.
The group probably looks as crappy to you as it did to me when i first drove down to inspect it. So to put it into perspective I put up a human like target against it since that is what the gun was meant to be used on.

Yep, I had a couple of flyers that I can’t explain. No excuse. I’m not as good as I was a couple years ago. It happens. I’m pretty happy with this. Had my spotter been my preferred partner and I shot from some sandbags I believe I may have been able to tighten this up a bit. Hand loads or the new Federal 73grain Berger gold medal load may have tightened it further. Those will be next time perhaps. I think the Q target demonstrates the ability of the MK12 with its issue ammo in knocking down human bag guys pretty well though.
In part 2 I will take the target out to the full 1,000 yards. This was my intention for part one but I anticipated terrible mirage from heat and wind and set the target up a little short. The temp and wind never did rise to the level I thought it would though and I was trying to shoot in those perfect conditions while I had the chance instead of wasting it driving back to re set the target. Next Time… 1,000 yards and maybe beyond.

