Mk 12 talk to me about this rifle.....

[Magwa]

OK I am all ears PRI Mk 12 SPR MOD H

[Matt.Cross]

What would you like to know? It's an evolutionary variant of the Mk12 Mod 0 and Mod 1 SPR role that began life in the special forces branches and has helped shape the role of the Designated Marksman in conventional warfare.

[98Z5V]

14 hours ago, Magwa said:

OK I am all ears PRI Mk 12 SPR MOD H

Call me.  What do you want to know, brother...  I got you...  

The Mod H was just the Mod 0, 5th Special Forces Group took out the 18" barrels and had 16" barrels installed by the unit (civilian contract BADASS) armorers.  They had PRI shorten up that full-length top rail, about in half.  Dropped the front sight gas block from PRI, went lo-pro gasblock under the carbon fiber handguard, because it was midlength gas.  They wanted something precise, but a little more maneuverable than the 18"-barreled Mk12 Mod 0s.  5th Group is also who came up with the Mk12 Mod 0s in the first place. 

SF runs Mod 0s and Mod Hs.  SEALs and Rangers run Mod 1s.

"Mod H" means "Mod Holland."  Named after MSG Steve Holland.  Precision Reflex is the only company that built either of these two rifles for 5th SFG(A), outside of the unit armorers converting the in-inventory Mod 0s they already had, and this was before NSWC Crane approval (on the Mod 0s).  So it you want one that's perfect, in build and design, get it from them, Precision Reflex.  Or, have me build it for you.  Or, I'll out the details and you can build the beast.  

I have a Mod H 6.5 Grendel - it's the one gun I'd pick if the bus showed up out front and said ":You can only bring ONE rifle..."  

Mk12 Mod 0:

Mk12 Mod H:

 

Precision Reflex website:

https://www.precisionreflex.com/

When you get here in the Fall, I'll bring out the Mk12 Mod 0, Mk12 Mod 1, Mk12 Mod H, and the Mk12 Mod 2.  You can shoot them all.  

Edited June 4 by 98Z5V

[98Z5V]

@Magwa - if you need a contact at PRI, let me know.  I have a good one.  

[Magwa]

wow thanks for the fast reports Matt Cross ,and 98Z5V this is exactly the kind of info I was looking forward to will call you in the next couple of days thank you both..

[98Z5V]

Hey, brother, no problem at all.  I'm here to help you spend your money...   In a GOOD way!...   

[98Z5V]

I'll gather up the Mk12s this weekend and get some pics and descriptions of them into this thread.  I picked up a match on Saturday that I never knew about, so that morning is out, but I'll get to it Saturday afternoon or Sunday morning...   

[Rsquared]

I've only completed the "Mod 0" of my MK12 builds so far. But I'm looking forward to getting back to building sometime soon. The "Mod 1" and "Mod H" definitely have my interest. As do other builds also.

[98Z5V]

1 hour ago, Rsquared said:

I've only completed the "Mod 0" of my MK12 builds so far. But I'm looking forward to getting back to building sometime soon. The "Mod 1" and "Mod H" definitely have my interest. As do other builds also.

Well, let's stop fukkin around and spend your money, too, brother!!!  

Build one of these Mk12s in the 6 ARC caliber.  Trust me on that.  

[98Z5V]

I'm not instigating or anything, but a 6 ARC Mod H would be the king.  My king right now is the 6.5 G Mod H.  I'm not taking it apart.  But, if I could make it a little bit better, I'd make is a 6 ARC Mod H.  

I'm just throwin' that out there...  For the crowd, you know...   

[98Z5V]

Did I tell you guys that we ran my 12.5" 6 ARC out to 1k yards, on target?  Did I mention that?  We hit 1.5 MOA steel, hit 1 MOA steel, and didn't make contact on half MOA steel - from a 12.5" gun...   As soon as that happened, I ripped the whole gun apart and redid it.  Made it better, stronger, faster - like Steve Austin, the 6 Million Dollar Man.  It's pretty cool, shooting a 12.5" barreled gun at a target 1,000 yards away, and hitting it.

Imagine what a 16" barrel Mk12 Mod H 6 ARC can do...   I'm just sayin'...  

Edited June 5 by 98Z5V

[98Z5V]

I'm not trying to sway anyone in any direction or another, but did I ever mention that I have 3 of the 6 ARCs?  One is that badass little 12.5" that went a grand, easy.  There are 2 more.  Both are LaRue full guns.  One is an 18", and the other is a 16".  It's the new LaRue stuff, too, where the handguard mounts straight up to the upper receiver via the flange.  Both of those were tested out to 1k yards, and the only difference in them was the 16 needs a few tenths more of dial after 700 yards, had slightly less speed - but it kept up with the 18" all the way out to 1k, with absolutely zero problems.

The only thing keeping those guns from being absolutely PERFECT, is that they ain't a Mk12. That would make them PERFECT.  And, I'd pick the 16" over the 18" all day long.  Mk12 Mod H that fukcer.  It does everything the 18 will do, with just a couple tenths more dial, all the way out to the max distances.  Might get 100 or 200 more max yards out of the 18, but at that point, both guns can do what I need them to do, and the range I need them to do it.  If it's beyond their range - WinMag.  After that, .338 Lapua.  After that - we call in direct air support, or start sending our mortars...   

Just my thoughts...   Food for thought...  

Edited June 5 by 98Z5V

[98Z5V]

6 ARC = Steve Austin...  I'm just sayin...  

6.5 Grendel is the most efficient cartridge ever developed for the small-frame AR-15 platform.

6 ARC just made it a little bit better.

I know where I'd go, if I wanted a Mk12 Mod H.  Now...

[Magwa]

Ok what about ammo supply? how easy or hard is it to find ammo if you can not load for it because the world is upside down ? I want to build a MK12 Mod H in 5.56 and shoot the 77 grain ammo is it available? just a effen badA$$ gun!

[98Z5V]

Factory ammo isn't going to be an issue, brother.  Even now, in these times.  

Hit up the Precision Reflex Incorporated website.  Sole Source right there, for the parts you're gonna need.  

Just like we talked about a little while ago, here's just the page to the rifles they offer, which are exactly what they would have built for SF Units if a call or procurement order came in.  There are 16 different rifles they will build for you.

https://www.precisionreflex.com/67-precision-reflex-ar15-accessories?q=Categories-Rifle+Packages

When you consider the cost of the components - and that barrel - the complete rifle packages are a steal.

STEAL - Strategically Transfer Equipment to an Alternate Location...   

[98Z5V]

@Magwa, embrace the Journey, brother, and enjoy the ride. Baddest 5.56 out there, designed that way with a purpose...  

 

[Magwa]

great video, pretty much explains everything from original and what you can do to upgrade today.....thanks

[Matt.Cross]

On 6/4/2026 at 11:07 PM, 98Z5V said:

Build one of these Mk12s in the 6 ARC caliber.  Trust me on that. 

Yea, verily! I can confirm that this is an optimization of the coolest kind for the platform. Tried, tested, proven.

[Magwa]

10 hours ago, Matt.Cross said:

Yea, verily! I can confirm that this is an optimization of the coolest kind for the platform. Tried, tested, proven.

for it to have a place in the safe it has to be common ammo so i will aim for 5.56 as you can find it everywhere not so easy with arc and I am not going to hand load for it.

[98Z5V]

@Magwa,  today is Sunday Funday!  Mk12 Day! I have the team assembled, and will get pics up soon.  Once you see the pics, fire any questions that you may have right at me...   

[98Z5V]

@Magwa, alright, brother, here you go.  I just want you to know that I just risked my life for you getting these pics.  It's 106* out here right now, and that brick patio - those bricks are about 130*...  And I layed down on them to get these pics...   I'm just sayin'...   

Mk12 Mod 0...

Mk12 Mod 1...   This one is a little different than spec - KAC rail was spec.  I prefer the LaRue rail, and think it's stronger.  And, it's got a 2 3/4lb lead weight from White Oak Armament in that buttstock.  If doesn't even WIGGLE when you shoot it...

Mk12 Mod H - the Mod Holland.  16" 6.5G caliber.  I didn't use the PRI shortened rail and scope rings - I went with a 1-piece scope mount to keep the weight down... 

Mk12 Mod 2...  This is my own creation.  If I could improve the Mod 1, this is what I went with.  Ditch the quad rail, and it's weight, and to an M-LOK rail - LaRue makes it.  Mod the buttstock to get it to transport easier.  Stuff this thing in a LITTLE bag - nobody is gonna think you have a fullon sniper rifle in that little bag...  

The whole Familiy:

That Mod H doesn't look that much smaller than the Mod 0, in this pic.  All the grips are lined up on the same line.  All the lengths of pull are very similar.  All the scope positions are very similar, in reference to eye relief...  But, that 16" isn't shorter than that 18"?!...  

Oh, yes it is - let's get you looking at the correct angle...

Fire off any questions you have.  I can answer any of it / all of it.  

[Magwa]

Wow I have been in the bush for a few days, thank you for the sacrifice of your skin on the pavement!!!!! i will call you to many questions to type  awesome looking collection!