MK12 Remastered

[BootyLord]

The DOD called and wants you to update the MK12. No caliber or price restrictions. Include optic/mount, muzzle device, barrel length & everything in between. What would your prototype look like?

Perhaps you’ve already built such a weapon, feel free to post a pic (again)

This thought experiment is obviously just for fun?

 

[Steel head]

While the mod 0 is basically AR perfection in my opinion I built mine with a more modern flair.

 

[TheMammoth]

Niet, rifle is fine.

Just kidding. As someone with a really close clone, and building a "my version" heres what I would (and am) changing:

-Cut rifle Bartlein barrel with port sized down for higher pressure hand loads
-VLTOR stock (personal pref, I have a lot of rounds on these and I do not have a beard. Its my comfort zone)
-NF 1-8 ATACR with Scalar works mount
-JP SCS tuned for hand loads
-Geissele SD-E
-various Geissele bit, bolt catch etc.


That's it. The top rail, hand guard, brake, silencer and other shit is all so nice it doesn't need updating.

Seriously, the AEM5 with knurling can is SO NICE if the fact that it is heavy doesn't ruin your day (I dont care, the tone is amazing). It's crazy how good it sounds even compared to some of the better modern offerings. The tone, the lack of back pressure, its cheap! it's a great system.

 

[Docsherm]

I already did.... 18" Noveske with a Rifle gas SwitchBlock, 12" LaRue Tactical rail, and a AAC Mini4 can (that is a SDN-6 in the picture).

 

[Docsherm]

It also has a single stage Timney 3lbs trigger. The upper and lower are a matched set from Rainier Arms. I have gone through several scopes. I can't find the one that i like the best. Currently it has a Vostex PST Gen II 3-14x44 Scope.

It loves MK262 ammo. I can get a solid .5 MOA or better at 300 yards. I have only had it out to 700 yards. I guess i could go longer but if i am going to do that i will use a differant rifle.

 

[bigjake83]

Done!

 

[TheGerman]

Go home DoD, you're drunk.

 

[MontanaMan]

Done!

View attachment 7163978

Yep, got the earlier version with the URX 3.1; no need to look further.

MM

 

[FromMyColdDeadHand]

Love my JP 18inch Rifle length adjustable gas upper with a Geissle 2stage trigger. Have a CQBSS 1-8 on it now, though a 3-15 is oh, so sweet. PRS stock was overkill. Looking to go from a Rifle stock to a UBR. With that 1-8, it is a steel assaulter out to 600 yards, down to 10 yards double tapping.

 

[AIAW]

According to SOCOM, this was the upgrade:

The Mk17 SS Optics Destroyer!

 

[87stang]

Done!

View attachment 7163978

You win!

 

[skatz11]

This is easy it’s a KAC SR15 LPR. If I were to start all over again I’d get one for sure.


A few years ago I modernized my MK12 WOA barreled modO clone with a URX4 and SF MB since I was never to go get around to getting the Ops/Allen suppressor. Now it’s an LPR wanna-be and I’m pretty happy with it.

 

[AEROMechanic]

It would need to be in 6.5 Grendel Why go with 5.56 at that point?

 

[AEROMechanic]

Done!

View attachment 7163978

If Knights could make that in 6.5G I'd agree.

 

[MontanaMan]

If Knights could make that in 6.5G I'd agree.

Ask & you shall receive, my son.

Non-cataloged item......................not the Grendel version, but one betta, though large frame required.

KAC 6.5 Creed Upper

MM

 

[Centuriator]

LMT has it covered.

 

[bigjake83]

It would need to be in 6.5 Grendel Why go with 5.56 at that point?

The 6.5G is ballistically superior to the 5.56 but it's not as reliable when running dirty, just ask people who put high round counts down range using a surpressor, once you get some grit and heavy carbon fouling that chubby little case in known for its FTE. The 224 Valk has a better chance then the 6.5G once they finally work out all the kinks.

 

[RyanScott]

Logistics is more important than ballistics in some cases.

 

[TheGerman]

It would need to be in 6.5 Grendel Why go with 5.56 at that point?

For a SPR, your considerations can't stop at just the rifle.

The 6.5Grendel is heavier, greater recoil, lower mag cap (not that big of a deal) and most importantly, shares zero redundancy amongst the rest of your element. SPR is still considered a primary weapon so its unlikely you'll be double bagging it with a M4 like I did with a M110/M24A2.

I know LRRP (forget his full username) likes 6.5G and uses it a lot, but as mentioned above, I'd utilize 6.5 in the KAC 6.5 upper for the large frame over 308 and leave the Mk12 where it is.

 

[RyanScott]

6.5G is a much better cartridge from the muzzle out. From the muzzle back it’s more complicated.

 

[Foxtrot2November]

How about a MK12 mod 3?

 

[_Windrider_]

224 valk

 

[bigjake83]

How about a MK12 mod 3?

Well i give you ??? for your choice components, please tell me you didn't cheap out on the barrel!?

 

[BootyLord]

The 6.5G is ballistically superior to the 5.56 but it's not as reliable when running dirty, just ask people who put high round counts down range using a surpressor, once you get some grit and heavy carbon fouling that chubby little case in known for its FTE. The 224 Valk has a better chance then the 6.5G once they finally work out all the kinks.

What kinks are you referring to? I’m curious because I’ve been considering re barreling my KAC SR15 (it’s not the LPR) to 224 valk. I’m sure that might sound like blasphemy to some but it’s a rifle I never plan on selling.

 

[tlsmith22]

When I built my MK12 clone I went with the NF NXS 2.5-10x42 instead of the clone correct Leupold. Then Leupold did a run of the cone correct scopes and I had to have one. I personally think I downgraded in glass there though. I love my MK12 and the AEM suppressor setup. Like shooting a 22lr when I shoot it suppressed.

 

[Foxtrot2November]

WOA SPR barrel sir

 

[bigjake83]

What kinks are you referring to? I’m curious because I’ve been considering re barreling my KAC SR15 (it’s not the LPR) to 224 valk. I’m sure that might sound like blasphemy to some but it’s a rifle I never plan on selling.

There are some debate on which Reamer is the correct one to use, even the guys at JP say it can be hit or miss with the Valk.(Pun intended) If that is something you're seriously contemplating on doing I would have Craddock do the work.

 

[MontanaMan]

If that is something you're seriously contemplating on doing I would have Craddock do the work.

2nd that comment; he seems to have it figured out & his work is excellent & he can do it with Bartlein, Rock cut rifled or Rock button rifled barrels depending on your preference. Or Criterion if you like that brand.

MM

 

[bigjake83]

"Or Criterion if you like that brand."

MM

Translation..... Don't be a cheap fuck on your barrel get a bartlein!...lol

 

[TheMammoth]

3rd for Craddock. And yes... just get a bartlein. I got mine from them and it’s gorgeous.

 

[Cheyenne Bodie]

Mod 0 Gen 3 in FDE, 6.5 Grendel, 18" match/boutique grade SS barrel, bored out AEM5. 8 mag top end magnification scope at least, with long range NV clip on and IR laser.

That's just a Mk12 idea I've had in my head, haven't settled on a barrel specifically.

 

[bbyars]

Translation..... Don't be a cheap fuck on your barrel get a bartlein!...lol

LOL Criterion and FN are some of the cheapest barrels i have in my guns but you may be surprised about the performance they will put out. Really surprised that no body has said LILJA.

 

[bigjake83]

LOL Criterion and FN are some of the cheapest barrels i have in my guns but you may be surprised about the performance they will put out. Really surprised that no body has said LILJA.

Cheap things usually do put out easy..

Holly shit, I just summed up my first marriage.

 

[MAC08]

18” 1:7 twist 223 Wylde chamber (the wylde chamber will eat both .223 and 5.56) White Oak SPR barrel rifle length gas tube with Badger .750 SPR Gas Block.

Knights 12" Free Float RAS MK12 Mod1 Quad Rail .

Muzzle break Allen Engineering AEM5 break and SPR collar.

Matched upper and lower are matched,

Trigger Geissele SSFA

VLTOR A5 stock system.

Scope mount Badger SPR NF NXS 2.5x10x24.

 

[TXBO]

WOA belongs in the discussion.

 

[digitalshooter]

I'd go with a:

UBR stock
Ergo Tactical Delux grip
Radian Arms Raptor Ambi Safety
Radion Arms Talon Safety
Geissele Super Select Fire trigger
Geissele Maritime Bolt Catch
Sharps Extreme Bolt Carrier Group
Geissele Super Charging Handle
V Seven Ultra Light Handguard
Superlative Arms adjustable gas block
Bartlein 1:7 LHT twist barrel in 223 Wylde by Compass Lake Engineering
Either a Primary Arms 1-8 Platinum with ACSS Reticle or a higher end scope with the ACSS reticle if the Primary Arms scope can't hold up to the rigors of combat. I think the ACSS reticle would be perfect for this application

 

[THEIS]

Hi,

Hey DoD....since we know how you love catering to some abominations at times...may I suggest to you the illegitimate child of the AR and Scar.....

Also--DoD...can you speed the BATFE review up for my importation of this product.
Also can you please explain that since an upper is not considered a firearm via BATFE standards then why do I have to get import license for said upper?
And more important is that IF uppers are not controlled by the BATFE yet they require an import license but yet they do not "Catalog/Test" just uppers why is it that I have to supply them with a full rifle for their catalog/testing?

Sincerely,
Theis

 

[Triple D]

There are some debate on which Reamer is the correct one to use, even the guys at JP say it can be hit or miss with the Valk.(Pun intended) If that is something you're seriously contemplating on doing I would have Craddock do the work.

And if not Craddock, I would recommend WOA. Their 224Valkyrie reamer works with the FGMM 90 and the inexpensive 75 AE loads. My barrel did need about 40rds to settle in, but after that, it’s been a consistent shooter.

 

[Steel head]

Interesting.
I’ve been considering a 224 Valkyrie barrel for my SPR build.

 

[Romeo458]

If anything use a 1-8 scope of some kind since it is considered a fighting rifle more than it is a sniper rifle, to use simple terms. Other than that it's fine really. 6.5 Grendel would be nice, but until the military swaps out all their rifles to it I don't see that happening, or making much sense in its role.

 

[The DFC]

Done!

View attachment 7163978

I couldn't disagree more. I have an LPR but still want a MK12

 

[MontanaMan]

WOA belongs in the discussion.

View attachment 7164876

Nice rifle, & yes, WOA surely belongs in the conversation..............mine shoot very well.

What scope model is that?

MM

 

[LeadZeke]

I think it is pretty clear that the Mk12 is supposed to be in whatever cartridge everyone else is carrying for logistical reasons not just on a large scale but on a small scale unit basis. If in this hypothetical scenario DOD changes everyone to the cartridge of choice....well that is a whole another can of worms. But regardless of the chosen cartridge, no matter if it is 5.56, .308, 6.5G, 6.5CM, .224Valk, etc. (outside of the new poiy case stuff) the ideal mk12 would be:

- Based on the AR10 or AR15 or the "hybrids" out there like the DPMS G2.

- Use DI/Stoner Gas System operation.

- Use a proper gas port size and placement for optimized use with a suppressor, but be able to run without one.

- Use a gas block seal like LMT's or KACs.

- Use an Inconel gas tube like V7s.

- Use an enhanced bolt like LMTs or KACs, and enhanced carrier like LMTs.

- Use lithium alloys like 2055 and/or 2099 for the receivers, extensions, handguards, etc like Hodge and V7.

- Use a monolithic or enhanced upper to ensure handguard doesn't torque barrel nut, and for easier use with NV like Seekins, LMT, or Larue.

- Use a Bartlein or similar high end cut-rifled barrel, gain twist, nitrided, using 5/8x24 threads. Length would depend heavily on cartridge chosen but I don't think any of them should be longer than 16in-18in or so max.

- Use a JP (finished BAT) barrel extensions.

- Use a Vltor A5 buffer used with Tubb's flatwire spring.

- Use a LMT's DMR stock or something similar that can be collapsed for use with armor but also offer a cheek piece and increased stability (the new B5 might be similar).

- Use a An AEM5 (or AEM30) made from titanium and with a flash hider "end cap."

- Use a quality two stage trigger like an SSA-E.

- Be issued with some quality match ammo, but be able to run whatever standard issue is.

Would basically improve on the current iterations in every way (depending on cartridge): weight, length, accuracy, durability/reliability, and so on. No one currently makes a rifle like this but KAC, LMT, and JP are closest.

 

[RyanScott]

I would use a 16” barrel made of similar materials and processes as the HK M27. Its accuracy is similar to a Douglas barrel but the life is many times that. Agree on using larger than standard threads, I think 3/4x24 is good for a 5.56 especially on a hammered barrel. 16” is long enough. I like the UBR for this, you don’t need a lot of adjustments and the height of your scope is controlled by the need for compatibility with clip-ons. The rail should have an Arca-Swiss section integral to the bottom at the balance point or full length, and should be 13-14” long. The silencer should be low backpressure and have minimal POI shift. Emphasis should be in reducing visual signature.

 

[RyanScott]

Oh, and it should be in 5.56 barring a change in standard issue caliber more broadly.

 

[TXBO]

Nice rifle, & yes, WOA surely belongs in the conversation..............mine shoot very well.

What scope model is that?

MM

Zero Compromise 420.

 

[hlee]

Sooooo, what does the mk12 not do that this replacement needs to?

 

[RyanScott]

It needs to be lighter, shorter, have a longer barrel and component life, less recoil, less visible signature and an improved optic.

 

[Qazwsx]

The chamber will have to be able to deal with m855a1.

 

[hlee]

Some of your requirements are at odds with each other... lol