A match made in hell.

Well maybe not hell, but it just doesn’t work.

Sometimes you see people who think that buying the best individual components and slapping them all together will result in the best results.  Sometimes that just doesn’t work.

For example, the rifle in this picture does not function.

The lower is a LMT MARS-LS, which some say is the best ambi lower on the market.  The upper is a Larue Ultimate Upper.

It doesn’t work because the UU upper has some additional material by the brass defector/ejection port.  That material pushes the right side bolt catch out causing the bolt catch to mash into the bolt carrier preventing it from moving.

This upper, and this lower are awesome on their own.  But together they are a non functional mess.

I’ll do a proper review of the MARS-LS after I have some trigger time on it.  But it won’t be with the upper in the picture.

A look at the 5.56 Larue Ultimate Upper

Some years back I wanted a Larue Tactical PredatAR upper.  They didn’t sell the uppers separately so I bought an entire rifle and sold the Larue lower.  I sold the lower for $500 and it sold in 15 minutes.

Guess I should have priced it higher.

At first mounted a muzzle break on it, and while that pretty much eliminated recoil on that light gun, but made for a gun I didn’t really enjoy shooting.

Later, I replaced the Surefire MB556 break with a Warcomp and the upper quickly became one of my favorite setups.  I later had it Cerakoted.

Light weight, smooth shooting, and accurate.

 

So I wanted more like that.  First, a similar rifle in .308.  So a while back I picked up a Larue 7.62 Ultimate Upper kit.  I ordered it about 4 months ago, I also ordered a lower to go along with it, which I am still waiting on.

I thought about picking up a second PredatAR.  But I saw there was the newer cheaper Ultimate Upper line.  The Ultimate Uppers are the newest in Larue Tacticals line.  You get a customizable kit including everything except a lower.  You have a variety of caliber options, barrel lengths, profiles, etc.  They have small frame options (AR15), and Large Frame.  In the Large Frame they have SR25/AR10 options and DPMS pattern.

So while the Larue 7.62 Ultimate Upper is pretty useless to me until Larue Tactical gets around to shipping me a lower for it, I have been really impressed by the kit.  So I bought a Larue 5.56 Ultimate Upper.

 

Unfortunately I wasn’t smart enough to snap photos of the 5.56 kit when it arrived.  So here is a couple of the 7.62 kit.

 

The 5.56 kit was similar.

I dunno why, but I decided to go with the standard weight 16 inch 5.56 barrel instead of the lightweight PredatAR profile.  I choose the MLOK over the Keymod hand guard option.  It seems to me that MLOK is winning the modular handguard war.

 

Larue added some sort of additional seal on the gas tube and gas block.  To quote Mark Larue, “It’s the new style – gas leaks bug me.”

The hand guard profile is quite small and narrow.

The upper kit was quick and easy to assembly.  I replaced the Larue muzzle break with a Surefire flash hider mount.

I initially threw an Aimpoint on the upper, made for a pretty handy configuration.

But I decided for the second outing that I would throw a Leupold MK6 on it and see what it could do.  I found I had a few rounds of Black Hills 75gr BTHP Match left, so I gave that a try.

I fired 3 rounds of M855 to get on target, then a couple of 3 shot groups (as I am very low on Black Hills match ammo).

Shooting at these 3/4 inch dots at 100 yards, my two quick 3 shots groups measured about 7/8 and 3/4 inch respectively.

So, I think it has potential.  I am going to have to do some more shooting for groups with this upper before I decide how it is going to be set up.

If the Leupold MK6 were to stay on it, I would move it forward as I prefer to shoot nose to the charging handle and I can’t do that with the current setup.

I really like the UU upper, and I think it is a great deal.  But I do need to point out a few things.

The UU upper is like a budget high end gun.  Larue changed the profile of the upper to something quite angular, most likely for ease of machining.  Less steps in the mill means faster and cheaper.

This angular profile is new to me.  I can’t think of anything similar from other brands.  The VLTOR MUR was similar, but didn’t take it to this extreme.

So, for example, it doesn’t have any profiling to blend into the curvature of the rear of the lower.

And the chamfer is extreme enough that there is a gap between the upper and lower above the mag catch.

So, if you are one of these nuts where fit and finish is the final say on if you like a firearm or not.  You have to decide if these little things would bug you.

Buying a UU upper lets you order a Larue lower.  But apparently on the factory assembled rifles they hand match the uppers to the lowers.  If you buy them separately with the kit, that won’t happen.  So once again, if you are a fit and finish freak, caveat emptor.

If not, I think the UU upper kits are a tremendous deal.  It does take away from the fun of picking each part your self, but you know you are getting quality and parts that will work together.

I really like mine.  Enough so that I ordered a Larue lower to go with it.  Now it is just to see how many months it will take them to ship it out.

Interesting Picture

I stumbled across this photo online.  I have no information about it other than the photo.  I saw it was referenced on a couple of forums I don’t have access too.

For all I know it could be airsoft, but lets imagine for a moment that we know it isn’t.

I used to hear that women could tell a great deal about a person by their shoes.  I’m not a women, so I have no idea if that is true or not.  But you can tell a little about a person by their weapons.

Lets take a look at some of the oddities of this weapon first.  Well I suppose we should look at the basics first:

It appears to be a HK416 or a cut down/rebarreled MR556.  The photo is somewhat blurry so I can’t tell if there is a third pin for full auto or not.  It has a Geissele scope mount which means this is a newer photo, but it appears to have a very old Surefire 4 slot flash hider.  This seems to imply the user has been using an old Surefire 556K for a long time.

Correction, it has been pointed out to me that it is the newer 212A 5 slot flash hider.

I’ve heard rumors of the combination of the old 556k and the 416 destroying guns.  I have no idea if this is true or not, when I had MR556 uppers I never ran them suppressed.

Back to the topic.  This rifle appears to have one of the new Nightforce 1-8x scopes which are pretty new.  That scope is sitting in a Geissele scope mount, which are said to be very good (and are extremely expensive).  I find it extremely ironic that this ultra tough non quick detach scope mount has been set on top of a LaRue QD riser.  This tells a few things.  The person who set this up wanted or needed the scope higher and/or needed the ability to quickly remove the scope.

They they didn’t just use a taller Geissele or Larue mount I don’t know.  If this is an issued firearm and they are using an issued Geissele scope mount this would be an example of the the wrong equipment being selected for the end user.

 

Then there is another aspect I find interesting.  There is an offset Aimpoint T-1, while the rifle has a 1-8X on it.   Aside from the offset T-1 and the light tape switch hinting strongly the the user of this rifle is right handed.  It also implies that they feel that switching the scope to 1x is either inferior or slower to just rolling the rifle and usign the offset T-1.  If they didn’t feel that way it would be unlikely that they would have the additional weight and cost of the T-1 on their rifle.

This person then is also doing something that warrants having 8x magnification on their 10.4 inch barreled rifle.  If it was simply for observation the user would most likely just carry something like a monocular or binocular.  Instead this person can use the 8x magnification on their rifle.

 

But my two biggest things I found interesting in this photo.  That the 1x on the 1-8x is some way insufficient and warrants still having a T-1.  That the Geissele scope mount is either too low or not QD and needed to be set on a Larue QD riser.

 

My first SBR.

A long time ago, in the ancient barbaric times of 2007, I finally had an approved Form 1 to make a Short Barreled Rifle (SBR).  Back then we didn’t have the pistol braces so doing the paperwork for a SBR was considered the best way to go.

I don’t remember why I choose to go get a SBR, but I have loved the short AR15 ever since.

I decided no expense would be spared, I would build a top notch SBR.  (Tier 1 wasn’t a phrase used back then, but that sort of mentality).

It was common knowledge back then that short AR15s were generally unreliable.  The LMT 10.5 inch upper was said to be the exception.  That it would “run like a raped ape”.  (It wasn’t till years later I learned that was a racist term).  LMT also used a medium profile barrel heavier than a standard M4 barrel on their 10.5 inch uppers.

I wasn’t going to use my old RRA lower for this, I would buy a brand new top of the line lower to build this top of the line gun.

So I went with a LMT lower.  The gun ended up looking like this:

Let me take a moment to explain some of the decisions and setups shown.

I wanted a flip up rear sight, so I went with the Troy rear sight I purchased for use in Iraq.  Troy sights are still an excellent product, but I much prefer to use other brands now.  Not to mention that the Troy Industries has done some questionable things since then.

I wanted to free float the barrel so I had a Larue 7.0 free float rail installed by MSTN.  It made for a very nice configuration.  Back then I wasn’t set up to build uppers, and MSTN was very highly regarded.  I believe they are still around but I don’t hear much about them.  I had him test fire the upper for me.

“YOURS IS BUILT AND GOT SHOT YESTERDAY. A FRIEND AND COWORKER WAS THERE
AT THE RANGE, AND I LET HIM SHOOT A MAGAZINE THROUGH YOUR UPPER.

HE ON THE SPOT DECIDED TO GET ONE FOR HIMSELF. HE WENT AND PICKED UP AN
LMT LOWER FROM THE SHOP WHERE WE DO BUSINESS AND HAS ALREADY SENT IT
OFF TO BE ENGRAVED.” Quote from Wes.

I choose to use a Diamondbond coated LMT Bolt.  MSTN was out of Diamondbond coated LMT Bolt Carriers so I purchased a coated Young MFG carrier.  I also purchased a second coated Bolt Carrier Group.  I’ll come back to this detail later.

A PRI Gasbuster was picked as it was the ultimate charging handle of its day.

I used the SOPMOD stock that came with the LMT lower.  I added a KAC QD sling attachment to the stock as back then LMT stocks did not offer a QD mount in them.

I used a CQD sling for a while back in Iraq.  I decided to go with CQD sling mounts on my SBR.  It was a good while later that I learned the SEALs were using the same mounts, I still think they were copying me.

Back then I think I tried every mainstream AR grip on the market. (No I didn’t use the one that let you put a revolver grip on your AR).  I eventually settled on the old A1 grip.  No finger bump.

For a while I ran the Eotech 512 forward mounted because the weight up front also helped reduce muzzle flip.

 

There were many many things I loved about that configuration, but it had a few fatal flaws.

Lets first talk about mistakes I made.

The LMT lower I purchased had an issue with its finished.  It was flaking off near the safety and the trigger pins.  I should have rejected it and had it replaced.

That sorta worked out ok with due to another mistake I made.

I had a local trophy shop engrave it for the NFA engraving requirements.  They really fucked it up.  I ended up having a pay more to send it off to Orion/TheGunGarage to have it properly engraved, the bad engraving fixed, and the lower finish touched up.  They work they did was awesome, but I shouldn’t have had to have that work done in the first place.

Back then some of the ammo I shot was Norinco.  This Chinese ammo seemed to lack the flash suppressant than most American ammo has.  When I fired my first round through this upper it made a tremendous amount of flash and blast and I instantly knew I was going to get a suppressor.  I wanted a Knights NT4, but my local didn’t didn’t have one and I let them talk me into a Gemtech M402.  The M402 is a good can, but ultimately wasn’t what I wanted.  Had I bought a NT4 I would probably still be using it as my main can today.

One of the biggest mistakes of mine was picking Eotech.  Back then, it was common knowledge that Eotech was great and Aimpoint sucked.  Just like how it was common knowledge that the world was flat.  Everyone knew that Eotech sights were faster, and because it used common AA batteries you could pull batteries of a remote to keep it running.  I didn’t know back then that I would have to room clear to the living room TV remote just to try and keep the Eotech running.

Now lets talk about the issues outside my control.

I had two Diamondbond LMT/YoungMFG bolt carrier groups.  One has been flawless, has seen tons of rounds, and just held up awesome.  It still resides in my favorite AR.  The other is. . . finicky.  That other coated LMT bolt causes random malfunction in what ever gun it is put in.  I was never able to figure out why.  It still sits in my parts bin.  That carrier however has seen tens of thousands of rounds of 5.45 and held up awesome.  Diamondbond is an amazing coating.

Chrome lined barrels can be very accurate.  LMT can make a very accurate barrel.  But my barrel was threaded poorly.  This wouldn’t have been an issue except I wanted to run a suppressor.

Either way this barrel had massive point of impact shift when suppressed.  10 minutes of angle.  That meant that I could either zero the upper suppressed or suppressed.  Since then I have multiple barrels that have had zero POI shift when suppressed, and that is what I have grown accustom too.

That was the ultimate deal breaker for me.  To not be able to quickly switch between suppressed and unsuppressed.  But I still love the 10.X inch barrel length on the AR.

Update on my firearm project.

Back around Hurricane Irma I got thinking about what I would get if I were starting my firearm collection from scratch.  I still have an unfinished article based off my musing I might post someday.

I’ve wanted a light weight .308 semi auto with a long handguard for a while now.  I really like the Colt 901 and would love to have one with a long handguard, but Colt doesn’t offer that in the US, so I went with Larue Tactical.

Larue Tactical offers what they a call an Ultimate Upper kit.  This is a somewhat customization kit that including everything necessary for a functional AR minus the serialized lower receiver.  These kits are a great deal for the money, but they tend to have a very long lead time so don’t get one if you are impatient.  If you buy one of their upper kits, you can also order a lower.

I place an order from LaRue on 6/21.

I held off for quite a while as the large frame Larue rifles are Keymod and I’d much prefer MLOK.  But after thinking about it I realized that I am just going to mount a QD mount for a sling swivel and a couple of rail sections, and never take them off.  For me, in the big picture, it doesn’t really matter which system it is.

The upper kit arrived on 8/10.

It is a nicely packed up kit of everything for a rifle except for a lower.

 

There is the option to purchase a couple more of Larue mags at a discount when you buy one of their UU kits.  These are mags are well made and are designed to allow for a little longer overall length on the rounds in the mag over other brands like the Magpul P-Mags.

I also purchased a Surefire Warcomp.  It reduces recoil but is not as blasty or loud as a proper muzzle break.  It will reduce muzzle flash more than a muzzle break, but less than a dedicated flash hider.  The other main benefit is the ability to mount my Surefire silencer.

I wrote a little bit about the Larue RAT stock here.

I decided to go with a light weight profile barrel, the same as on the PredatAR rifles.  The barrel with gas block and gas tube weights 2 lbs 5.6oz.  I choose a light weight barrel as I know I won’t be doing high volume fire through this gun, and I do know that Larue makes accurate barrels.  The 308 rifles have plenty of weight in other areas, so I think this will be a good compromise.  Worse case scenario, the gun can be re-barreled, but I doubt that will be an issue.

To put it in perspective, the Proof Research lightweight barrel is advertised to be 2 pounds 3 oz at $940.  I don’t think 3ish ounces is worth that premium.

Barrel is marked Rearden Steel.  That’s for those of you who get the reference.

The gasblock is keyed the barrel for alignment.

Three setscrews hold the gas block in place.  Flat bottomed holes are cut in the barrel for these set screws.  I used Rockset to help secure them.

The match two stage trigger and pistol grip that comes with the kit is installed on a dry fire trainer so you can test the trigger as you wait for a lower.

I have no idea how much longer I am going to have to wait for the matching Larue lower I ordered for this kit, but I will write about it when I get it.