MK 12 Mod 0 or Mod 1 clone build

[KevinB]

I'm with DocGKR on this issue,

I've played with barrels from 4" (M2Corp) to 20" in 5.56mm

the 16" middy with a S&B Short Dot is IMHO the ideal GP carbine - its not perfect for CQB - and if your role is specific to that the 10-12" systems are much better (I still have not bought a 12.5" yet - give me time)


As for the 18" versus the 20" - While in the CF I had access to a true reflex suppressor (BR-Tuote from Finland) (as long as it was not viewed as QD repeatable zero) it offered a 20" barrel suppressed in the same lenght as the Mk12 with the OPSINC suppressor (althought the OPSINC did not exibit the 2 MOA POI shift)





- I have had problems with the PRI gasblocks - the one on the above rifle got knocked out of alignment in Ft Benning and turned it into a single shot for the remaineder of the day until the armorer re-aligned it.

However it was a much better system than the boat anchor that the CF decided to adopt

[michealj]

I am thinking of building a Mk 12 clone, either mod 0 or 1. Any info or advice?

I personally love the look of the Mod 0, so that is what I went with. If you go with the Mod 0 get the Ops Inc. 12th Model silencer to go with it if you can, you will not be dissapointed.

[C4IGrant]

Some thoughts:

I've used the original SPR with the PRI parts and Leup 3.5-10x, as well as the Mod0 and Mod1 using the Leup 3-9x.

For pure shooting I like the original SPR and Mod0 and have an early one built by the original Crane vendors. The Mod1 is a better field rifle.

However, currently, there are better options than either one.

Many of the best builders have moved away from the rifle length gas system on 18" barrels in favor of mid-length. There is virtually nothing that an 18" SPR can do that a 16" Recce/Recon can't do about as well, given equally good barrels and optics. Rather than a Mk12 , these days I'd go with a good 16" Recce--probably a Noveske using a LaRue rail and an NF or S&B scope in a LaRue SPR mount.

Kinda interesting that there are two schools of thought for barrel lengths: 10/14/18 or 12/16/20 and I'm tending to lean towards the latter these days.

I would have to agree. The PRI tube looks nice, but I have had some issues with them in the past so I do not use them.

I try and explain to customers that call that the Mid-Length gas system is the best all around system, but they still want the rifle length one.

Below is an old gun I built for myself to shoot varmints.



C4

[Rogue7a]

https://www.m4carbine.net/attachment...7&d=1164242069

[K.L. Davis]

Purpose built... Not rifle length, nor midlength
Picture from www.militarymorons.com (my camera skills still suck)

[Rogue7a]

1. Vltor "A1" length butt stock
2. Vltor Upper
3. Accuracy Speaks Full Auto Trigger (3.5lbs and Breaks like glass)
4. ARMS #38 SPR Rail (Modified to fit PRI GENIII Hand guards)
5. ARMS #22M Rings with front "Tactical Ring Cap"
6. Krieger 1/7 BBL (DCM Heavy under hand guards)
7. PRI GenIII Hand Guards
8. GG&G Bipods
9. PRI Flip up Front Sight
10. PRI Gas buster Charging Handle
11. OPS Inc. 12th Model MBS
12. Doctor Optic (Beat up from multiple tours, replacing with Larue Rig)
13. AN/PVS-22
14. ARMS #40 Low Profile flip up rear sight
15. Leupold SOCOM MKIV M2 3.5-10x40mm w/ illuminated TMR

After break-in we are getting sub 1/2 moa using MK262 MOD 1

[Rogue7a]

- I have had problems with the PRI gasblocks - the one on the above rifle got knocked out of alignment in Ft Benning and turned it into a single shot for the remaineder of the day until the armorer re-aligned it.

However it was a much better system than the boat anchor that the CF decided to adopt

Kevin,
Honestly, i have NEVER heard of someone having more problems with things coming loose on a MOD 0 then you Crazy K'nucks. I can only think of a couple reasons why this happened (And sorry to say that they are ALL operator headspace and timing issues)

1. Try using "Standard" size vs. "Metric" tools during assembly. ('cause the parts are "American" made)
2.Refer to proper torque settings
3. Red Loc-Tite

I mean "jeeze" my SPR averaged 2 tours without any issues and yours can't even stand up to a plane ride from the Great White North to Benning.

[KevinB]

I don't build guns I take to work...

[Rogue7a]

I don't build guns I take to work...

That must be some of that "French Canadian" humor

Well technically I don't "Build" my "work" guns either.

However,
My "Mechanic" must be smarter then yours (Actually a monkey with an armorer wrench AND Red Loc-Tite)

You should fire the one working for you.

I mean it only goes together one way......

No hard feelings my beer drinking, jelly doughnut buddy from the great white north.

Just messing with ya

[DacoRoman]

hey guys, new dude here great forum!

It looks like the Mark 12's have rifle length gas systems correct? Is there a difference in reliability between a mid length and rifle length gas system when using an 18" barrel? Or would one change the gas tube diameter when going down to a mid length? In other words what is the optimal gas tube length for an 18" barrel?

thanks!