LaRue, Colt, KAC Battle Carbines Compared Part 2

Part 1 is located here.

I wanted to do an informal precision and shooting comparison between these three rifles.  From left to right in the picture there is a Larue Ultimate Upper kit, a Colt LE901-16SE, and a KAC SR25-EC.  The Colt and the KAC are used rifles, the Larue kit has only had about 32 rounds thought it at this point.

Last weekend I took the three rifles out and fired them at 100 yards using three different types of ammo.  For the test I used a Leupold MK6 3-18 power, and fired the rifles from a Cadwell rest and rear bag.  I singled loaded each shot and fired a 5 shot group with each ammo type.

My initial intent was to fire 5 rounds from each rifle cycling between the rifles before switching brands of ammo.  Unfortunately the point of impact was different enough between the rifles that I was initially off paper as I moved the scope, so I ended up firing all the groups from one rifle, then moving to another.  I used the same firing position, scope, target frame, etc with each rifle.  Fortunately weather and shooting conditions stayed consistent through the course of fire.

Before starting, I expected the Larue to group the best and the SR25 to be the easiest to shoot due to its weight.

I am glad it was an informal test, as I ran into a bunch of issues, mostly all my fault.  I was using my phone to snap photos and I dropped it and broke it very early on.  It was a good thing I had already planned to single load the shots for the groups, as I left all my .308 magazines at home.  The Larue kit comes with a PRI Gasbuster charging handle which I loved, until I cut my trigger finger good on the corner of it.  Good thing I don’t get paid to do this.

An aside, so as my trigger finger was slowly bleeding, I was looking at the medical supplies in my car.  I had something like 3 tourniquets, 2 chest seals, a nasopharyngeal airway, a decompression needle, lots of large pressure dressings, etc, but no band-aids.  I ended up staunching the trickle of bleeding using a McDonald’s napkin I had in my car.  Note, I need to add boo-boo gear to my car medical supplies.  I’m pretty sure McD napkins aren’t considered high speed-low drag, or even clean & sterile bandages.

Anyways, shooting went ok.  Of all the strings of fire I only felt like I pulled 2 shots.  I will bring them up when I discuss the groups.

The targets side by side.

First, the SR25-EC. The EC has a 16 inch heavy barrel that is chrome moly (not chrome lined).  Twist rate is 1:11.

I was surprised, I found the SR25-EC the hardest to shoot of the rifles off the bench rest.  I had expected the combination of it being the heaviest rifle along with the rifle length gas system would make it the lowest recoiling and smoothest shooting rifle.  Firing it off the bench I felt like it had the most movement out of all the rifles when I was shooting it.  This may be in part due to the KAC rail covers being ribbed and as the rifle recoils that may have caused more visible movement though the scope.

  • Hornady American Gunner 155 gr BTHP
    • I fired a 1.42″ 5 shot group
  • Hornady Match 168 gr BTHP
    • This gave me a tighter 1.25″ group.
  • Federal Gold Metal Match 175 gr
    • The first shot landed rather far away from the rest of the group.  Ignoring the first shot, the rest of the group is .77″  Including that first shot the group is a little over 1.7″

I didn’t feel like I pulled any shots or did anything noticeably wrong during those strings of fire.  I am rather disappointed that I didn’t shoot better groups.  I can’t say at this time if it was the rifle or me that was under performing.

The Colt rifle has a chrome lined 1:12 twist rate.  It appears to be that the intent with the 901 is to have an accurate combat rifle, verses say something like the Larue rifles where are meant to be a reliable precision rifle.

The Colt LE901-16SE standard trigger made it a little harder to shoot groups with than the other two rifles.  I found the VLTOR stock on the rifle didn’t fit in the rear bag as well as the CTR stocks that were on the other rifles for shooting.  In hindsight, it might have been nice to use the same stock on each rifle so that they would fit the rear bag the same.  The slick forarm of the SE rode the front bag nicely.

The 901 was the only rifle where I felt that I had a 2 pulled shots.  When I fired the 4 shot of the Hornady 168gr BTHP match I pulled that shot left.  On the 5th shot of the FGMM I had a bug land on my neck as I was pressing the trigger and I jerked the hell out of the trigger in surprise.  I am sort of surprised that shot was even on paper.  But I suppose that lack of discipline is why I was a rifleman and not a sniper.

  • Hornady American Gunner 155 gr BTHP
    • We had a ~1.69 inch group.
  • Hornady Match 168 gr BTHP
    • Excluding my pulled 4th shot, the group was about 1.5 inches, including that shot 1.9″
  • Federal Gold Metal Match 175 gr
    • Excluding my pulled shot, the group is .95 inches.  Including it it is a 1.62 inch group.

Using FGMM 168gr, I have shot sub 1 inch groups with the Colt LE901-16S, and this rifle in the past.

Between each group, I took a break and and would touch the barrels to make sure they had cooled off.  My no means a reliable test, it seemed to me that the 901 got the hottest.  That just seems weird to me.

The Larue Ultimate Upper kit can be ordered with a variety of different barrel options.  This one has the lightweight PredatAR profile.  It is a 1:10 twist rate.   Rifle rifle having the lightest trigger, a nice smooth long hand guard, and the muzzle break was the easiest and smoothest to shoot by a noticeable margin.

I was surprised and disappointed with how the Hornady ammo shot in this rifle.
  • Hornady American Gunner 155 gr BTHP
    • This 5 shot group was 2.1″  I was pretty surprised and disappointed at this.  3 shots landed in .54 inches, but those were the first, second, and 5th shot.
  • Hornady Match 168 gr BTHP
    • This 5 shot group came in at 1.56 inches.  Best 4 of 5 would be .93 inches.
  • Federal Gold Metal Match 175 gr
    • Now this performed more like what I expected.  The 5 shot group is approximately .93 inches, best 3 of 5 being about .53″.

I’ve never shot the Hornady American Gunner or their 168gr match before.  I don’t think I am ever going to buy it again when I could just buy the FGMM instead.  All three rifles put at least 4 rounds of the 5 round group of FGMM in under an inch.  Normally when I would shoot for groups with factory .308 I’d use the FGMM 168 gr.

I was making sight adjustment between groups, and I found that the FGMM 175 gr ammo was impacting about 1 mil (3.6 inches) low compared to the loads at 100 yards.  This was consistent from rifle to rifle.

So what are my takeaways from this?  No more factory Hornady ammo for me.  I believe each of these rifles could do MOA or better with the Federal Gold Medal Match ammo, but unfortunately one five shot group with that ammo doesn’t really tell the true performance of a rifle.  I’d love to just sit at the bench and do a bunch of groups from each rifle but I not sure if I will get the chance to do so.

I’ll be posting up a part 3 which will compare some the internal parts.  I find it interesting on how the Larue rifle has a much lighter recoil spring than the others and feels like it is cycling in slow motion compared to the others.

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.