Precision gas gun, Form?

[NSI]

I am slowly losing patience with my 14.5" LMT and these dog@#$% groups. (this is 20 77 AAC OTM in 2.5", slow fire with an ATACR off a Rokblok).

Feeling the need...for a PRI.....



-J

 

[wind gypsy]

I am slowly losing patience with my 14.5" LMT and these dog@#$% groups. (this is 20 77 AAC OTM in 2.5", slow fire with an ATACR off a Rokblok).

Feeling the need...for a PRI.....

View attachment 743742

-J

My 14.5" BCM does similar.

This thread got me jonesin for a mk12 but ive seen enough stuff out there that makes we worry that I might be at risk of being unsatisfied with precision if i got one..

One example:

There have been some groups Form has posted on scope test threads with one that didnt leave me envious either.

 

[CMCctx]

My 14.5" BCM does similar.

This thread got me jonesin for a mk12 but ive seen enough stuff out there that makes we worry that I might be at risk of being unsatisfied with precision if i got one..

One example:

There have been some groups Form has posted on scope test threads with one that didnt leave me envious either.

In my experience, the barrel choice followed by proper installation/fitting of the rail (rail section hardware contacting the barrel in a lot of instances) is the sticking point with most bad experiences. I've only done a Mod 1 with KAC FF RAS, Mod H with KAC URX4, and NSW Recce with KAC FF RAS, but they've all been wicked.

 

[NSI]

In my experience, the barrel choice followed by proper installation/fitting of the rail (rail section hardware contacting the barrel in a lot of instances) is the sticking point with most bad experiences. I've only done a Mod 1 with KAC FF RAS, Mod H with KAC URX4, and NSW Recce with KAC FF RAS, but they've all been wicked.

Not to be slick - but the LMT monolithic upper is pretty hard to eff up.

What does wicked mean to you? If you have a formula for sub-1.5" 10 round groups from a 5.56 gas gun with factory 77 grain ammo, I'm truly all ears with an open wallet. The fact Henry couldn't get that out of the PRI mark 12 upper across 5 ammo types is what's giving me pause.

The Ridgeline guys are printing a 5" sub-inch group with each LPR they sell, which I suppose is a start, but is susceptible to cherrypicking.

Rifles - Ridgeline Defense

ridgelinedefense.com

-J

 

[Formidilosus]

My 14.5" BCM does similar.

This thread got me jonesin for a mk12 but ive seen enough stuff out there that makes we worry that I might be at risk of being unsatisfied with precision if i got one..

One example:

There have been some groups Form has posted on scope test threads with one that didnt leave me envious either.

There are several points here.

1). When not cherry picking, gas guns are not as consistently precise as bolt guns.

2). Gas guns are more finicky in regards to from and consistency of the shooter. Lock time is a thing.

3). Rest matters more with gas guns than bolt guns- almost every shot from this MK12 has been from a tall bipod.

4). Gas gun ammo matters a lot. Blackhills MK262 is not really “match grade” ammo- it is usually between 1.2 to 2 MOA for 10 rounds from good gas guns. That is the ammo that I mostly have shot with this MK12 and pictures here. I have lots and lots of 10+ round 1 MOA groups with other ammo.

5). The MK12 is an ultra reliable combat rifle first. It is not a bench gun, though it shoots like a 3 gun rifle.

6). This rifle has more than 6,000 suppressed rounds, with some very aggressive firing schedules without a single thing done for barrel cleaning or maintenance.





Overall with ammo made specifically for this rifle, or ammo that it prefers, 10 round groups are frequently less than 1 MOA. 30 round groups are 1.1 to 1.2 MOA. Yes a WOP upper with tuned load will average sub 1 MOA for 10 round groups from a bench; but it will also be much heavier, the same or similar finickiness in ammo, and still subject to the shooter variances as any other good upper.


In all that, MK12’s aren’t for everyone or for everything. If you care more about group aggregate above everything else, WOP is an easy swing. If you want an 18”, super soft shooting, extremely reliable in all conditions, suppressed rifle that is sub 2 MOA every single day regardless of conditions or abuse, that holds zero unerringly, and maintains POI regardless of forend torque- the MK12 Mod 0 is one of the best options, and in mine and quite a few others experience- the best overall option.

 

[Formidilosus]

Not to be slick - but the LMT monolithic upper is pretty hard to eff up.

LMT monos are almost without question the best extremely hard use AR15 upper platform on the market. But their barrels aren’t “match grade”- most are 1.5-2 MOA for multiple 10 round groups with most good ammo. D. Wilson can spin up an LMT barrel with a Bartlein, Brux, etc. that will shoot excellently.

What does wicked mean to you? If you have a formula for sub-1.5" 10 round groups from a 5.56 gas gun with factory 77 grain ammo, I'm truly all ears with an open wallet.

Sub 1.5 MOA for 10 is not hard with correct ammo choice and a legit barrel/upper.

The fact Henry couldn't get that out of the PRI mark 12 upper across 5 ammo types is what's giving me pause.

Not being a douche, but I wouldn’t take very many people’s groups with a gas gun as much of anything.

The Ridgeline guys are printing a 5" sub-inch group with each LPR they sell, which I suppose is a start, but is susceptible to cherrypicking.

Rifles - Ridgeline Defense

ridgelinedefense.com

-J

Yeah…. 5 shot groups under an inch with a PRI MK12 is not remotely unusual.

 

[rbutcher1234]

While I disagree on the objective conclusion of mod 0 over a mod 1 based only on nostalgia and personal attachment, I certainly agree that a ops 12/AEM5 is a must. Phenomenal can.

 

[wind gypsy]

Damn this thread. Just saw that otter creek and b&t make lighter versions of the ops 12 too.

 

[Cactus kid]

, that holds zero unerringly, and maintains POI regardless of forend torque- th

The maintaining POI regardless of forend torque was an interesting selling point of the ridgeline defence rifle. I did not know this was a thing with gas guns till recently. Do all mk12 mod 0 uppers have this quality? What is needed in a build to keep this POI shift from happening?

Are you familiar with the ridgeline rifles at all?

 

[Formidilosus]

The maintaining POI regardless of forend torque was an interesting selling point of the ridgeline defence rifle. I did not know this was a thing with gas guns till recently. Do all mk12 mod 0 uppers have this quality?

If they are correct MK12’s, yes. The handguard and attachment is quite stiff, and then the full length pic rail attaching the receiver and handguard together make it very stiff/strong.

What is needed in a build to keep this POI shift from happening?

A monolithic upper (LMT) is really the end answer. But, a very strong/stiff forend and barrel nut, and then tying the forend with the upper receiver is what makes the best setup for a conventional upper.

Are you familiar with the ridgeline rifles at all?

I am familiar, though no personal experience.

 

[CMCctx]

While I disagree on the objective conclusion of mod 0 over a mod 1 based only on nostalgia and personal attachment, I certainly agree that a ops 12/AEM5 is a must. Phenomenal can.

@rbutcher1234 was one of the main reasons I got mine. I was waffling whether or not to, then I was peer pressured into my favorite can. I then got a Gordon M4 from Ron Allen which is still currently homeless until I can figure out something that I like it on. Nothing that it works with is objectively better than the AEM5, so AEM5 gets the love. Even over the Hyperion, which was also purchased under the direction of the homie.

Not to be slick - but the LMT monolithic upper is pretty hard to eff up.

What does wicked mean to you? If you have a formula for sub-1.5" 10 round groups from a 5.56 gas gun with factory 77 grain ammo, I'm truly all ears with an open wallet. The fact Henry couldn't get that out of the PRI mark 12 upper across 5 ammo types is what's giving me pause.

The Ridgeline guys are printing a 5" sub-inch group with each LPR they sell, which I suppose is a start, but is susceptible to cherrypicking.

Rifles - Ridgeline Defense

ridgelinedefense.com

-J

@NSI I was just referencing the barrel contact issues that I've seen other people have when installing rail sections to PRI tubes, and a few instances of top rails (SPR and Recce) impacting accuracy. I can't absolutely confirm one way or the other because I've never owned a PRI tube. I should have said "In my experience observations". I thought the last part about the only ones I've done were with KAC rails made that clear but I can see how my opener was misleading.

 

[Cactus kid]

A monolithic upper (LMT) is really the end answer. But, a very strong/stiff forend and barrel nut, and then tying the forend with the upper receiver is what makes the best setup for a conventional upper.

Thanks for the reply- any functional difference between a semi-mono vs monolithic upper? I have a lot to learn before I make a purchase

 

[Formidilosus]

Thanks for the reply- any functional difference between a semi-mono vs monolithic upper? I have a lot to learn before I make a purchase

It would depend on which one as to how oh different. But, there is no getting around that splitting the receiver and handguard can only make things weaker.

Have you used an LMT mono upper?

 

[Cactus kid]

It would depend on which one as to how oh different. But, there is no getting around that splitting the receiver and handguard can only make things weaker.

Have you used an LMT mono upper?

My experience with any gas gun is minimal. Spend all my time and money on bolt guns, just now thinking about a precision gasser. How you describe the mk12 is how I want the rifle to perform, but I was sold on the ridgeline platform cause I’m a sucker for good marketing

 

[Formidilosus]

My experience with any gas gun is minimal. Spend all my time and money on bolt guns, just now thinking about a precision gasser. How you describe the mk12 is how I want the rifle to perform, but I was sold on the ridgeline platform cause I’m a sucker for good marketing

Ah. Well, an LMT monolithic upper with an after market barrel is the most bomb proof precision AR on the market. Everything else is a compromise. The MK12 Mod 0 is in a separate category just due the total package, but for all other AR’s, the LMT the way.

 

[NSI]

Ah. Well, an LMT monolithic upper with an after market barrel is the most bomb proof precision AR on the market. Everything else is a compromise. The MK12 Mod 0 is in a separate category just due the total package, but for all other AR’s, the LMT the way.

Say I go the D Wilson route with my LMT. Should the smith who chambers the barrel (prior to sending to DW for conversion) have my bolt in-hand when cutting the chamber? I'm not sure whether headspace in an AR is a GOOD/BAD scenario or whether the chamber size actually matters for precision as in a bolt gun.

-J

 

[Formidilosus]

Say I go the D Wilson route with my LMT. Should the smith who chambers the barrel (prior to sending to DW for conversion) have my bolt in-hand when cutting the chamber? I'm not sure whether headspace in an AR is a GOOD/BAD scenario or whether the chamber size actually matters for precision as in a bolt gun.

-J

It doesn’t really matter. All they really do when they chamber a barrel is check headspace with the bolt.

 

[Cactus kid]

Ah. Well, an LMT monolithic upper with an after market barrel is the most bomb proof precision AR on the market. Everything else is a compromise. The MK12 Mod 0 is in a separate category just due the total package, but for all other AR’s, the LMT the way.

Dare I ask what the difference is between the mk12 build vs the LMT? You are talking to a dummy when it comes to these things

 

[NSI]

Dare I ask what the difference is between the mk12 build vs the LMT? You are talking to a dummy when it comes to these things

$900 for the upper

LMT MRP-L MLOK 13.25" Upper Receiver Chassis | Rooftop Defense

Buy LMT MRP-L MLOK 13.25" Upper Receiver Chassis | The MRP-L MLOK 9.25 is the carbine length upper receiver designed for 14.5″ barrels up to 20″ barrels.

www.rooftopdefense.com

$677 for the barrel

.223 Wylde Bartlein Barrel

craddockprecision.com

$125 for the conversion

LMT MRP Barrel Conversion

www.dwilsonmfg.com

TOTAL: $1,702, figure $1,800 after components (gas block, tube, etc.) and shipping.

All of these uppers are in the same neighborhood, interestingly:

PRI: $1,777

18" Mark 12 Mod 0 SPR Gen II Upper in 5.56 Cal. 1-7 Twist

This Gen II Mark 12 Mod 0 5.56 caliber 18" upper is a complete upper with all the extras and ready to shoot. Upper is a M.O.A accuracy 1-7 Twist barrel. Available in Black and Flat Dark Earth. Note: Upper Assemblies have a flat rate shipping fee of $15 per assembly to the Continental United...

www.precisionreflex.com

RD15 LRP: $1,800

Upper Receiver - Ridgeline Defense

The AR-15 is without question America’s Rifle. It has been our Nations chosen Service Weapon for over 60 years. It has defended our streets, our homes, and our homeland, but it was never intended to be a precision rifle. Throughout the 1990’s Armorers from Special Operations Units came up with...

ridgelinedefense.com

-J

 

[Remington92]

$900 for the upper

LMT MRP-L MLOK 13.25" Upper Receiver Chassis | Rooftop Defense

Buy LMT MRP-L MLOK 13.25" Upper Receiver Chassis | The MRP-L MLOK 9.25 is the carbine length upper receiver designed for 14.5″ barrels up to 20″ barrels.

www.rooftopdefense.com

$677 for the barrel

.223 Wylde Bartlein Barrel

craddockprecision.com

$125 for the conversion

LMT MRP Barrel Conversion

www.dwilsonmfg.com

TOTAL: $1,702, figure $1,800 after components (gas block, tube, etc.) and shipping.

All of these uppers are in the same neighborhood, interestingly:

PRI: $1,777

18" Mark 12 Mod 0 SPR Gen II Upper in 5.56 Cal. 1-7 Twist

This Gen II Mark 12 Mod 0 5.56 caliber 18" upper is a complete upper with all the extras and ready to shoot. Upper is a M.O.A accuracy 1-7 Twist barrel. Available in Black and Flat Dark Earth. Note: Upper Assemblies have a flat rate shipping fee of $15 per assembly to the Continental United...

www.precisionreflex.com

RD15 LRP: $1,800

Upper Receiver - Ridgeline Defense

The AR-15 is without question America’s Rifle. It has been our Nations chosen Service Weapon for over 60 years. It has defended our streets, our homes, and our homeland, but it was never intended to be a precision rifle. Throughout the 1990’s Armorers from Special Operations Units came up with...

ridgelinedefense.com

-J

Knock 15% off the pri from Brownells at the moment.