Military operator reviews SCAR

fluwoebers, who must be in one of the SOCOM units, has written a must-read review of the FN SCAR, both light (5.56mm) and heavy (7.62mm) models.


Reciprocating Charging Handle
I remembered to keep my thumb down most of the time, but while practicing switching back and forth between strong hand and week hand, the charging handle caught me.
My thumb slowed it down enough that it caused a FTF.
It was not painful enough with 5.56 to learn my lesson.
I did it again with 7.62. That hurt.

“Softness/Brittleness” of plastic
The polymer is very dense.
It is a little on the soft side, so it is not likely to crack very easily.
It is not so soft though that it bends or deforms easily.
It feels like a pretty good balance in strength and rigidity.

Bottom Line:
The SCAR is a good system. I’m not ready to give up my M4.
As the SCAR evolves over the next couple years, it will be a top-of-the line rifle.
I’m not convinced that it is worth the cost to purchase and train on a completely new system.

I highly recommend reading the whole review. It is very comprehensive.

Big thank you to Jay for emailing me the link to the review.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • solomon

    thanks…not flaming the other site but the discussion at the end didn’t add anything to my knowledge. anyway you can get a hold of the guy to do some decent reporting on it?

  • Brad

    Very interesting review.

    I think the SCAR lower cyclic rate is a real improvement compared to a typical AR. That improvement might be the decisive edge in the USMC competition for the for the new Infantry Automatic Rifle.

  • Matt Groom

    No, sir. I don’t like it.

    Not one little bit.

    The only reason this thing has gotten as far as it has is because the Belgians have clout, since they already have the contracts for GPMGs and M-16A4s. They got the XCR disqualified and it was pure politics.

  • Vitor

    Yeah, colour me unimpressed. A review comparing the SCAR with the HK416 would be super nice.

  • Jeff M

    What ever happened to the ACR?

  • jdun1911

    “The hinge itself is made of polymer”

    Plastic hinge are not good.

    “It is difficult to judge with as few rounds as we put through them.
    Not everyone had exactly the same experience with reliability.
    This is probably something that needs larger sample size and more controlled testing.
    Bear in mind that these were brand spanking new guns. We had to clean the cosmoline off them.
    They may have needed a little break in.
    FTE: I had one FTE at the very end of the 4th mag. It looks like the brass either didn’t clear the ejection port, or deflected off something and ended up back in the ejection port.
    FTF: I had 2 double-feeds around 500 and 700 rounds.

    I had two other failures that were probably caused by outside factors.
    1st: The reciprocating charging handle struck my thumb and caused it the gun to short stroke.
    2nd: While shooting with the gun sideways, almost touching the ground (simulating shooting under cover), I had another double feed.
    I’m not sure how that would have caused this, but it was under unusual shooting conditions, so I’ll give it the benefit of the doubt.”

    Five jam three of which is double feed. That’s unacceptable. The double feed is a cause of concern because it takes longer to clear and you lose a magazine.

    “I also tested function with the gas regulator on the wrong setting.
    Shooting non-suppressed with the setting on suppressed, the gun short stroked about every 5th round.

    FTE: none
    FTF: I had 2 FTF with the MK17; a double feed on the second round fired and a double feed half way through the 5th mag.

    When testing function with the gas regulator on the wrong setting, I had the same result as with the MK16. ”

    Too many double feeds for my liking and I get the impression he was not the only one that is experience it.

  • Sean

    i concur with mr. groom. i think the ACR could give that SCAR a run for it’s money.

  • jdun1911

    The ACR won’t be coming out anytime soon.

    Bushmaster has all the tools and molds needed to start production last year from Magpul. In fact Bushmaster could have shipped them out to dealers around Nov. IIRC.

    When Bushmaster heard about the new Army rifle completion, they decided to hold off. They wanted to know all the requirements in the new program which should be available around Nov. of this year.

    Both system is probably flawed because Author Miller has pointed out that the AR18 action in order to work reliable needs to use double recoil spring. Both the SCAR (modified) and ACR relies on a single recoil spring.

  • Matt Groom

    The recoil springs are not an insurmountable flaw, so long as they used a heavier gauge of wire and made the spring a larger diameter, it will be strong enough to work well enough with an AR-18 gas system. It is a serious problem for the SA-80 (or whatever they’re calling it now).

    jdun1911 is right about the ACR being in limbo. The Magpul engineers that I’ve spoken too seem to be somewhere between skeptical and outright pessimistic on that dog ever seeing the light of day. I can never get a straight answer out of the people from Bushmaster, which means they really don’t know anything more than we do.

    The major flaw I see in the Masada/ACR (I will continue to call it the Masada until somebody else actually produces an ACR or whatever) is that it uses a Johnson/Stoner bolt. All piston driven ARs suffer from the same faults with sheared off bolt lugs, and the Masada will be no exception.

    The SCAR is only a slight improvement, since they went with a different bolt that has lugs completely missing on about 1/3 of it’s circumference, I am skeptical of the SCARs long term durability as well, but probably most of the plastic parts will break several times before that bolt does.

    Cerberus now owns such a large chunk of the AR market that perhaps they are reluctant to create a rifle which will compete with that market, even if it uses many AR parts. No, it doesn’t make sense to me, either.

  • Well, I just wanted to say I don’t know squat about the SCAR so this has been a good read. Thanks!

  • jdun1911

    In the May 2009 interview of Small Arms Review Author Miller said having a larger heavier spring will not work. I forgot his reasoning but they did try it and the result was not good.

    What I recalled, that around 800 rounds the spring will start to lose it strength and malfunction will happen more. By using double recoiled spring the elastic limit will not be reach. So basically the springs will last for a long time.

    Small Arms Review is the only gun magazine that worth the time to read. Check it out.

    ACR use the AR18 action so it won’t have the same problem as the AR15 DI where the locking lug will break. This is because most of the stress is directed at the bolt. This is not the case for the AR18.

    • jdun1911, thanks for the info. I must subscribe, I have been meaning to for a while.

  • Matt Groom

    jdun1911: I read that, too. Aurthur Miller said that the single spring that was only marginally stronger than the one of the two recoil springs used in the AR-18 was the problem with the SA-80, not that single recoil springs will never work with that gas system. It can work, witness the H&K G36, the Brits just did it wrong. H&K did two things to the SA80 when they did their product improvement program, and that was polish all the sharp corners, and add a stronger single recoil spring.

    I agree that two springs are superior. You may note that some newer designs, such as the Kel-Tec RFB, use two recoil springs instead of one. They are not absolutely essential in most designs.

    The problem is not the gas system, and for all intents and purposes, the DI gas system is actually better than most, including the AR-18. This is because the bolt is actually pushed forward as it rotates to unlock, which takes the stress off of the lugs. The gas pushes directly on the bolt as well as on the carrier, which causes the bolt to unlock. The best version of this system to date IMHO is the Zitta system used in Para USA’s TTR.

    With a conventional piston driven system, which by design is pushing on the bolt carrier outside of it’s central axis, the bolt is pulled backwards against the lugs as the carrier moves. This creates stress on the lugs, as well as friction and heat. The piston, whatever it’s design, pushes a bolt carrier, which pulls the bolt. The weak design of Johnson/Stoner bolt is due to the unequal distribution of forces around the circumference of the bolt and the locking surfaces of the lugs. The lugs nearest to the extractor will be under the most stress, and the ones opposite those two will be under more stress than the others. This is not a big deal when the bolt is pushed forward during rotation, but when it’s pulled, it gets bad.

    The carrier being pushed off of it’s central axis by the piston, usually from the top means that it wants to go in the opposite direction, usually downward, tilting at it’s center of gravity. This creates a sea-saw effect on the carrier and causes it to tilt very slightly as it travels reward, which causes the bottom end of the rear of the carrier to drag, as well as the top end of the front. This creates legions of problems in an AR upper, and excessive rail wear on other designs, such as the FAL and the SCAR. This is described quite admirably in part 1 of the Small Arms Review interview with C. Reed Knight, Jr., February 2009, Vol. 12 No. 5.

    Apologies to Steve for my long posts.

    • I encourage long posts!

  • XxleoxX

    im 14 so i can barely understand what you talk about,but i used to be in love with the SCAR. But after reading the whole review, too many double feeds and from what i read its too much plastic, Im gonna switch to the HK416 as my new favorite.

  • Matt Groom

    @ XxleoxX:

    Keep it up, kid. The only way to learn it is to teach yourself. I was a teenage gun nut once. Now I work in the industry. I got the greatest job in the world, and all of my friends are doing lame-ass conventional stuff. You won’t learn this stuff in school, it is VERBOTEN.

    P.S.: H&K thinks you suck, and they hate you.

  • Ken

    LOL Matt with the HK comment….I remember looking at my personal AR15 when I was a kid.Also,my m16a2 when I was in the Army.The fact of the see-saw action of the carrier plus the gap between the carrier and the upper receiver “bore”, leads to more stresses on the lugs to some degree. Granted said “gap” is there because they don’t want a grain of sand(lol) seizing up the works and also expansion of the 2 parts due to heat. Personally, from an engineering standpoint,Ive never like the small locking lugs. Especially the ones so close to the extractor.

  • XxleoxX

    ken why must u confuse me? :/ my personal opinion is that plastic and guns dont go good together

  • jdun1911


    HK are decent overpriced firearms. You can get much better firearm at a lower price then HK. Glock and CZ comes to mind. HK416 as well as other piston AR type have a lot of flaws that must be overcome.

    Plastic firearms are bad. The only plastic gun that worth a damn are Glocks.

    Ken, the see-saw affect applies to piston AR and not DI AR.

    DI AR receiver will last forever.

  • Matt Groom

    Plastic in guns definitely leaves me cold. It has it’s place, like stocks, grips, frames, and mag followers, but hinge pins, locks, mag catches, selectors, guide rods or any part that will be under significant stress, plastic is a big no-no. The Euro-Peons are fond of using plastic trigger components, not just the trigger, which I frown on, but in the sear, the selector, and even the hammer. Socialism makes people soft and disposable, so perhaps that explains their affinity for soft materials in disposable firearms.

    Sig uses a plastic hammer in their P250
    H&K uses plastic hammers in their G36/SLR-8
    FN uses plastic hammers in their FS2000 and SCAR

    What the hell’s the matter with these people? Haven’t they heard of Forgings?

  • Ken

    I agree Matt.Funny how the prices for the guns dont reflect the cheap crap they are made of. Also seems to be a scam too,make high stress parts outta plastic and they will break easy and therefore be in high demand.

  • jdun1911
    • jdun1911, very interesting. I may blog it shortly. No reason why they could not have made a metal insert.

  • Burner

    That’s an Advanced Armaments Co. silencer they are coupling it with. That’s a change from Gemtech, I believe.

  • badassweakling

    Why are they still using the older 18 tooth suppressor mounts with their suppressors?

    The newer 51 tooth suppressor mounts are far superior, and have been out for almost two years now.

    Are the SCARs going to stick with the 18 tooth mount indefinitely?

  • Lance

    I agree with the article Im NOT a SCAR fan myself. Too much plastic and a flimsy butt stock. I uch prefer the HK-416 or the new Colt Advaced carbine. I do read of alot of Spec Ops units in the Navy refusing to hand over there M-4 for SCARs. I think the most promising rifle that the Delta Force tried and liked is the HK-416.

  • Destroyer

    I view the skepticism with the SCAR no differently than how the M16 was treated during its introduction. Reading from the review, the SCAR was brand spanking new, so unsurprisingly, double feeds occur during the break in process because of the tight tolerances.

    If polymers and plastic work better than metal, then i have no problem using them. The SCAR is just in its infancy, though it amuses me how quick everybody is to “forget” about the M16’s flaws when it was first introduced. It is not just “plastic”. It is a specified polymer. Similar to saying a Romanian AK is the same as a Russian one because it is “made of metal”. Generalizations are very rarely true.

    I have yet to see the “see saw” effect on gas piston AR15’s (that DI mongols are always screaming about). I must have awesome luck, because the three models that I own work quite well despite thousands of rounds going through them (bushmaster XM15 ES2, LWRC M6A2, and Olympic Arms with a osprey defense conversion kit). I enjoy my civilian SCAR 16S (as well as its competitor, the Robinson XCR) and will see how long it lasts versus AR15 rifles of direct impingement and gas piston operation.