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LaRue, Colt, KAC Battle Carbines Compared Part 1

Happy Thanksgiving all.

Today I am thankful that I got to try a few different rifles this morning.  I did side by side shooting of a Larue 7.62 Ultimate Upper rifle, Colt LE901-16SE, and a KAC SR25-EC.

It isn’t really fair to directly compare these as there are some major differences between them.  Sort of like comparing apples to apples to oranges.  But that never stopped me from being critical about things before.

This first comparison will be short.  I had these three rifles available to me so I decided I would start with 20 rounds each rapid fire with an Aimpoint T-1.  I would do some rapid engagements of a target at 10 yards, and do some double taps at 10 yards.  I ended up firing 32 rounds from the Larue due to functioning issues, and only 20 from the others.  Not exactly a comprehensive test, but a start.

From top to bottom, KAC, Larue, Colt.  20 round groups rapid fire off hand at 10 yards.  Mostly rapid pairs.

I shot the Colt LE901-16SE first.  When Colt release the 901, they first released the LE901-16S, which was a full railed model.  I believe they sold a few -18S with an 18 inch barrel.
After that, they release the -16SE.  They shaved a pound off the rifle by replacing the quad rail on the monolithic hand guard with a proprietary modular rail.  This model appears to have been discontinued and the newest model, the CM762 adds an ambi safety, longer MLOK hand guard, and an ambi charging handle.  The new model is also available in 6.5 Creedmoor with a 18 inch barrel.

The rifle is is stock configuration with a Aimpoint T-1 added to it for the comparison.  With the exemption of the lack of an ambi safety, I found the controls on this rifle to be the best.  The right side bolt release is easier to hit, the larger and lower left side mag release gives more leverage and is easier to use.

The list weight on the -16SE is 8.4 pounds.  When I shot it I found it tended to recoil straight up.  I felt that it was fast and easy to shoot, but my performance on paper was the worst with it.  Back when I the 901-16S side by side with the 901-16SE, I found that that 1 additional pound of weight made the fully railed 901-16S have much less felt recoil.

The Ultimate Upper is an economy large frame rifle kit from Larue Tactical.  You can purchase the upper kit in SR25 or DPMS pattern.  If you buy a kit you can buy a Larue lower for it.  This isn’t really a fair comparison to the others as I added a Surefire Warcomp to this rifle.  The Warcomp can drastically reduce recoil.  I think this gave the Larue the major advantage in shooting.  But I had multiple short strokes when shooting the Larue.  I fired an additional 12 rounds at another target trying to diagnose the issue and trying out the offset sights.

The Larue lower is the only one of the bunch that isn’t ambidextrous.  I find the bolt catch on it harder to use than the one on the 901.  Not hard on its own, but less easy than the 901.  The receiver extension on the Larue is AR10 pattern, but doesn’t have the hole locations to collapse the stock completely.  The photo above shows the stock as closed as it will go.  This made the UU kit rifle longer than the others.

The Safety Level that Larue includes in their parts kit is horrible.  I have two of these Larue safeties and they don’t move positively.  Several times when I was bringing the rifle up for a fast aimed shot, attempting to flick the safety off it would only move half way.  I did not have any issues with the safeties on the other rifles.

The recoil spring on the Larue is much lighter and easier to work the action than the other two .308 rifles.  Felt more like racking a standard AR15.  When firing the action felt like it moved much slower than the other rifles.  I think this also made it feel more controllable and easier to shoot well it – when it worked.  Compared to the others, shooting the Larue Ultimate Upper kit felt like shooting one of the other rifles in slow motion.  I’m going to start calling this the LTUU762 for Larue Tactical Ultimate Upper.

Unlike the others, the KAC SR25-EC uses a rifle length gas system on the 16 inch barrel.  I had always heard that the KAC SR25 were so extremely smooth shooting.  Much to my disappointment it didn’t seem any better than the others.

The SR25s for a long time not have come with ambi controls.  The right side safety is scalloped and the rifle has a right side bolt release.  The rifle weighs about 2 pounds heavier than the other rifles.  This was noticeable in the handling and recoil characteristics.

When shooting the SR25-EC it recoiled straight up.  Settles right back down on target.  To me it seemed like it had similar recoil to the 901, but the 901 is about 2 pounds lighter.

I think it was the lighter two stage trigger on the KAC that helped me shoot it rapidly better than the standard AR15 trigger on the 901.

So?

Right now, if I had to pick one for a fight it would be the 901.  Even thought I shot it worst in this side by side comparison, it is far lighter than the KAC, and the LTUU7.62 is currently unreliable.  I previously had a Warcomp and match trigger in the 901, and it drastically reduced recoil and made it easier to shoot.  I returned it to stock before this comparison.

I’ll be talking more about these rifles in the future.

A look at the Larue billet OBR lower

Larue sells their billet AR15 lower for $199 and their SR25 pattern 308 lower for $299.

I ordered a Flat Dark Earth (FDE) Larue Tactical billet lower almost 5 months ago.  It finally came in.

It looks like the FDE lowers are anodized a light tan then painted over it.  The coating might be Duracoat.  The inside of the lower, trigger pin holes, etc are all left uncoated.  You a little bit of the paint overhanging the top edge of the receiver.  Also note that Larue added a flange where the receiver extension screws in.  We will come back to that later.

The lower looked perfectly made with the exception of the final thread on the lower was a little deformed.  This caused a little resistance when the receiver extension was screwed in, but was ultimately a non-issue.

This picture betters the distinction between the lowers natural finish and the coating.

The magwell has a very nice flair to it.

The trigger guard is nicely scalloped.

Bolt catch is held by a standard roll pin.  The lower is notched in case you need to remove it.

When I started assembling the lower with the Larue parts kit, I first tried to use an aftermarket ambidextrous safety.  The aftermarket safety was binding on the finish so I switched back to the Larue safety.  I don’t care for the slop in the Larue safety.  In the safe position it has lots of slop (as pictured above) and the movement is not very positive.  I have a second Larue parts kit and the safety in that one is exactly the same way.  Minor disappointment 1.

First I was going to use a different end plate with QD sling swivel attachment.  I found it would not work with the Larue receiver extension.  Minor disappointment 2.

Here is where I got frustrated.  Using a Larue Receiver Extension, on a Larue Lower, they don’t fit together.  The receiver extension hits this flange in the lower.

There is a post on AR15.com forums where Mark LaRue explains that he has his guys just use a sander to make the receiver extensions fit.  I spent a couple of hours trying to find that post, but I couldn’t.  I’ll edit this if I find it.  Link here.  


There’s nothing wrong with the tube.

I had forgotten that when I laid it out, I did so with extra material on it that was dressed/sanded to fit in-house in the gun room. 
Reason being that timing the threads on lower and receiver extension was a no-go. 
My guys screw it together, sometimes randomly the threads are timed, others need a kiss on the sander. 
ML 

ETA – there is a machined-in v-block feature that cradles the rear of the bolt carrier, that’s very much worth having, but makes it a little different when it comes to the installation of the extension.

Mark Larue

So I ended up having to spend some quality some with a sharpie and a bastard file to assemble the lower.  
After all these decades of various manufactures making interchangeable AR parts and Larue Tactical decides to make their own parts not fit together with out modification.  That doesn’t seem right to me.

In the end, I now have an assembled rifle.  I threw the T-1 on it for fooling around, I think I’d rather keep some magnification on this.

I like the Larue billet lower, but I don’t think it is worth waiting 4-5 months for.  For far cheaper there are a variety of other .308 SR25 lower options.  I forget the brand, but last month there was a sale where stripped uppers and lowers pairs were about $100.  In all truth, I actually order a different lower when this one finally shipped.  I’ll write about the other one later.

For those who want a complete Larue brand rifle and want to build it them selves, the option to buy a Larue lower is great.  But if you really look at the dollar value, you can do better elsewhere.

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.