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KWA Full Metal KM4A1 Carbine AEG Airsoft Rifle

Airsoft ShortyUSA (c)


$ 299.99

Regular Price: $ 329.99
You save: $ 30.00 (9%)
Shipping: $ 8.99

Average of 4.70 reviewed by 33 people
This item has 33 customer reviews
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Released in July of 2009 the 2nd Generation KWA KM4A1 features numerous improvements for greater reliability and smoother performance.

The original KWA KM4A1 was one of our best AEG’s however for 2009 KWA has polished this gem even more. They have redesigned the metal Version 2 gearbox by adding more reinforcements to the front half of the shell and have used 9mm bearing bushings on all three gears now. The gearbox is still factory upgraded to professional competition level which includes their high performance spring, steel gears, poly carbonate piston, aluminum piston head, metal air nozzle, metal spring guide w/ bearing, high torque motor and 16 gauge wiring.

With this much hardware in the receiver it is not surprising that this rifle can unleash some unnerving firepower and have the precision to put it where you want it. Using only an 8.4v 1400 mini type battery this rifle will spit out over 16 rounds a second and with its high torque motor the trigger delay is not even noticeable making double taps a breeze. Its high compression cylinder coupled with the its powerful spring produces 400 fps w/ .2g at the muzzle. Its 395mm barrel has been fitted with KWA’s 2G hop-up bucking which gives the rifle more consistent accuracy making it effective to 180 feet or more. For best accuracy and range we strongly suggest using heavier .25g BB.

This M4 has all the best features when it comes to its model. It has the same metal content as the real firearm with a strong yet lightweight aluminum receiver that even has a functioning dust cover and a mock bolt that moves when you pull back on the charging handle. The carry handle is removable to reveal a weaver mounting deck to which you can attach an endless assortment of accessories to. Built into the carry handle is a fully functional A2 rear sight with adjustable windage and elevation. And last but not least it has a six position LE style collapsible stock for added versatility in tight quarters.

  • Please note: You can download the owners manual in PDF form from the KWA website here:

    This KWA product comes with a 45 day warranty provided by KWA USA. Warranty repair or replacement on this item must go through the KWA service center and does not fall under the Shorty USA warranty.

    Click for more information on the KWA LIMITED 45 DAY WARRANTY.

    If you are getting one of your first AEGs please take a moment and read the following Hints and Tips for AEG owners.

    Please click on the orange hyperlinks to view more information!
  • Operation: Electric
  • Fire mode/s: Semi / Full Auto
  • Muzzle velocity: 400 fps w/ .2g
  • Effective range: 180 feet
  • Rate of fire: 1000 RPM
  • Ammo type: High polished .2g - .25g
  • Hop Up: Adjustable
  • Weight: 7 lbs
  • Magazine capacity: 350 rds (Wind Up High Capacity Magazine)
  • Length: 30.5 - 33.75 inches
  • Battery: Mini Type 8.4v, Double Nun-Chuck 9.6v or 10.8v. (Does NOT work with Windhorse 9.6v 2400mah NiMH XL Double Nun-Chuck)
  • Motor: Long Shaft Type
  • Inner barrel: 395mm
  • Comes with orange tip: Painted
  • Battery and Charger NOT included

    ©2009 Shorty USA Inc. Property of Shorty USA Inc. Duplication for commercial purposes is expressly forbidden.

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    KWA Full Metal KM4A1 Carbine AEG Airsoft Rifle - Quantity:


    C U S T O M E R   R E V I E W S

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    Reviewer: M16er
    Rank: GEN
    Location: Branford, CT
    read all my reviews
    60 out of 65 people rated the following review helpful:

    5 out of 5- Just Got This Today...Recommended

    As you may have seen in my most recent review, I said that I was going to order this baby soon. Well, I did, and it arrived at noon today. I was busy and could not write my review until now, however I did have time to fire it twice, and I put about 400 BB's through it so far.

    When I first opened it I realized how realistic it was, especially with the metal body. Although, anybody out there that has handled the real steel Colt .223 like myself can safely say that it is night and day, please don't get me wrong the KWA is honestly a very great replica.

    The magazine is very cool. If you look at it a certain way in the light it turns almost to a shiny silver color. It's hard to explain, but if you own a KWA then you probably know what I'm talking about. Unlike the ECHO1 magazines where you have to wind them every 10 shots or sit there and wind for a minute or more, the KWA requires about 20 seconds of winding and fires about 295 of the 300 BB's. Also unlike the ECHO1 magazines where there are about 15-20 BBs left in the magazine, the KWA only leaves about 5 BBs in there, which is really nice for easy clean-up when you put it away for the day. The magazine hasn't had any mis-feeds so far.

    The retractable stock is awesome. It is very solid and I have no complaints. Sorry that I can't elaborate more on this, but there isn't much to talk about except that it is great quality and has 6 positions.

    The foregrip is very realistic, too. Just like the real steel, it is extremely solid and very hard to remove. It's actually a two man job for my dad and I. This can be annoying for battery installation but the realism out-weighs the annoyance. Inside the foregrip it's quite spacious. I can easily fit my Intellect 9.6v 2000mah nun-chuck battery in there. There is also plenty of room for the 10.8v battery listed here on Shorty if you were wondering.

    The performance is outstanding. It is very accurate considering that it doesn't have a tightbore barrel. The FPS is pretty good. I call anything above 430 FPS great, but don't get me wrong because 400 FPS is plenty. The RPM is the best part. I was shooting in semi-automatic for the first half mag/150 BBs and I couldn't wait to do the fully-automatic short burst break in. Finally, the time came. When I tell you this is a BB hose, believe me it is. Rated at 950 RPM with only an 8.4v mini battery according Shorty, this baby is easily doing 1100 RPM with my 9.6v 2000mah nun-chuck. By the way, it is rated up to an 11.1v lipoly battery so don't be afraid to get a very powerful battery. The hop-up is very smooth. My ECHO1 M16 hop-up is way too tight, and barely movable. My ECHO1 MP5 hop-up is way too loose, and gets turned down when the BB passes through because it forces the hop-up nub back up. The KWA is perfect. It's extremely easy to move and also stays in one place and is not changed by the passing BB. I also love the distinct sound it makes because of its aluminum piston head. It's hard to explain this noise, and you will only understand it when you have shot a gun with a plastic piston head and a gun with a metal piston head.

    Buying a KWA is definitely worth it. You get insane reliability, performance, and realism all in one package, which I would have thought impossible a few years ago. It is pricey but if you buy an ECHO1 and upgrade it to a KWA equivalent you will spend probably double the price of the KWA itself. Sorry for the long review, but if you want to buy this gun then we both know you didn't waste your time and this benefited you greatly.

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    Reviewer: Ferraro B22
    Rank: GEN
    Location: Rancho santa margarita, CA
    read all my reviews
    25 out of 39 people rated the following review helpful:

    4 out of 5- KM4A1 Carbine 2nd Gen.

    I know i've said it before, but all the new AEGs are impressing me. 400FPS AND 950RPM? Just a year or two ago, i wouldn't have thought this possible.

    Range (although 150ft is basically standard for any decent AEG)
    Adjustable hop-up
    Adjustable stock
    Functional dust cover
    *Almost every aftermarket upgrade is made for M4/M16s
    Weight (for some)
    Mag cap
    Full metal

    Doesn't come with battery or charger
    Weight (personally, i like a gun around 6 LBs)
    *Range could be better
    *Price (this brought it down from 5 to 4 stars)
    Can't use large type batteries

    *Big Pro/Con

    This is what i suggest:
    1, Stealth operator
    KM4A1 X1 $300
    130rd mid cap X3 $ 30
    10.8v Custom X1 $ 50
    M4/M16 mag clamp X2 $ 18
    Smart charger X1 $ 30
    Spec ops reflec sight X1 $ 10 (or the $30 red dot)

    OR $438 s/h
    2, "Spray and Pray" kinda guy
    KM4A1 X1 $300
    M4 box mag X1 $ 50
    10.8 Custom X1 $ 30
    Smart charger X1 $ 30
    $410 S/H
    Overall: Great gun. Buy it if you have the money.
    P.S. Don't follow my advice, that was just to give you newbies to airsoft ideas.

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    Reviewer: xXKra5hXx
    Rank: MG
    Location: vandergrift, PA
    read all my reviews
    18 out of 24 people rated the following review helpful:

    5 out of 5- Best gun for your Buck

    This is definitely the best gun with no needed upgrades or anything


    405 Fps
    Full metal

    Price(for a few)
    doesn't come with battery
    Range(actually not that bad)

    If you want a gun get this.

    My Setup:

    Kwa M4A1
    Utg Quad Rails
    2x 10.8v
    4x40 scope
    weaver riser
    Gen 3 sling

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    Reviewer: illestgamer33
    Rank: LTC
    Location: milpitas, CA
    read all my reviews
    12 out of 18 people rated the following review helpful:

    5 out of 5- the best aeg ever!!!!

    i bought this gun at a local airsoft store...sorry shorty..they gave me a deal!! but on to the gun. out of the box this gun was extremely squeaks or wiggles of any sort. i loaded up the mag and test fired it..410 fps!!!well i wanted more so i put a gaurder 130 spring in it and now it shoots 500 fps with .2g.oh and the great thing about this gun is that's all you need to gear upgrades, no motor upgrades..all the stock internals are already upgraded. i put a 6.01 tightbore barrel on this and it's so accurate. i'm also running an 11.1v lipo battery and the rof on this is insane! 25 rounds per second!!! this gun is a beast and can handle a lot of abuse. i'm using .28g to bring my fps down to 450 and for better accuracy.

    for anyone looking for a great aeg that's already upgraded out of the box, this is the gun for you. for the price it's well worth it. i've had mine since the 2nd gen came out and have had no problems with it at all. also i've tried multiple mags and most work and some are a tight fit. just try them before you buy to make sure they feed properly.

    definitely get this gun. it rocks!!!

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    Reviewer: Cornia2
    Rank: CPT
    Location: Cardiff, CA
    read all my reviews
    11 out of 16 people rated the following review helpful:

    5 out of 5- Amazing Gun!!!

    Very good gun!!!! Extremely accurate and high rate of fire!!! Recommended for anybody who wants a very decent gun!!!

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    Reviewer: Neon Soviet
    Rank: 1LT
    Location: Weston, MA
    read all my reviews
    10 out of 16 people rated the following review helpful:

    5 out of 5- Sweet

    I had been trying to buy a great aeg for along time. I looked at everything, from mp5's to augs, p90's, ak's, thompsons, SAW's and even custom guns. My search narrowed out to one gun, the KWA M16, one of the most customizable guns on the market. I did not think of an M4 because of the lack of a large battery in the good ones like KWA and G&G, and UTG was making full stock ones but the internals were bad. Then I saw this gun, it looked sweet, was like the KWA M16 but had a little less range, was $30 cheaper, but still did not have a big battery compartment. But then Shorty got the battery pouch (I forget name, starts with W) that allowed a large type battery to be attached on the stock, and did not look like crap as the battery boxes do on the front end of your gun. For all you people that hate mini batteries like I do, there is a solution finally. With the larger battery in the pouch, cqb sight and not orange tip this thing is probably the awesomest aeg i have ever seen. For all you people that hate mini batteries like I do, there is a solution finally.

    T.I.W.A.W. Put a new flash hider on this gun, it takes away the orange tip making the gun look a whole lot awesomer. (Bet you don't know what T.I.W.A.W. means)

    A.T.I.W.A.W. Also I hate the people that do Pros and Cons, there are too many of them.

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    Reviewer: brentsonk
    Rank: 1SG
    Location: Hilo, HI
    read all my reviews
    8 out of 11 people rated the following review helpful:

    5 out of 5- awesome gun!!! buy it

    This KWA KM4A1 is a really good gun.

    great fps
    rof (rate of fire)
    full metal

    doesn't come with a battery or charger


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    Reviewer: airsoftguy111
    Rank: COL
    Location: Verona, NJ
    read all my reviews
    8 out of 9 people rated the following review helpful:

    5 out of 5- GET THIS GUN!!!

    This is an all around great gun.

    Fps- fine, it could be around 420 but 400 is fine.
    Accuracy- great.
    Mag cap.- pretty good, if it was 500 rnds it would be better but 300 is pretty
    Weight- just right.
    Feel- just right.
    Rpm- pretty good, if you compare it to a mini gun this thing rules for the price,
    if you compare it to most aegs this thing is a beast!

    This is really the only annoying thing about the gun...
    It DOES NOT come with the charge or BATTERY!!!

    Shorty, you make a lot of good products, but could you PLEASE at least include the battery?!

    Overall, a great gun.

    !!!___---WAR STORY---___!!!

    MY friend let me borrow this gun in a war to see how it handled...

    OK, so it was 5 vs 5. My best friend, and 2 other teammates got sniped when we were advancing into enemy territory and me and my other teammate had just sprinted back to our fort (without getting shot). It was then 2 vs 5. The other guy on my team was ahead behind a tree keeping a look out. He saw a guy come out of the bushes, the guy saw him, dropped his gun, and shouted "Blue". The guy on my team (not knowing what "blue" meant stepped out into the OPEN (idiot) and shot him. Then out of the bushes popped the other 4 guys and he went down easily. It was then 1 vs 4... the 1 being me and me alone with this gun my UHC 1911 and 1 spare mag for each gun. The 4 guys split into teams of 2 to hunt me down. I jumped into the bushes to hide (and purposely made a lot of noise). 1 of the teams came running at the bushes and I put about 5 rounds into each guy's chest ((we play if you don't get hit in a vital part of your body you have to be shot at least 3 times there to be out) they were a pretty stupid team... none of them even had back up weapons). I jumped out of the bushes and ran straight into the other 2 guys (just my luck)... One of them was the sniper who put 10 rounds into my friend's back. I stepped back thinking "I'm SCREWED" but with my luck... both their guns jammed when they tried to shoot (they didn't have back ups like I told you before... Again, with my luck, the mag fell out of my gun (because i accidentally bumped the release switch so I snatched the one out of my back pocket, rolled to the side (just in case they were faking the jams) and flicked my gun into semi. However, no sniper puts 10 rounds into my friend's back and gets away with it... so... I put it back into full and decided to be a jerk. I unloaded the whole mag onto them (about 150 rnds on each of them).

    This gun is a beast, every time I get into situations like that (which is like every war I don't know how) something goes wrong. NOTHING went wrong with this gun as a I have proved.

    peace out

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    Reviewer: oW0LFo
    Rank: 2LT
    Location: Omaha, NE
    read all my reviews
    7 out of 9 people rated the following review helpful:

    5 out of 5- Best Gun you can get!!!

    This gun is really the best gun you can get...

    Not going to lie, it is expensive!!! but mom bought it!!! haha - sucker

    anyways, it is reliable like crazy, won't break, and shoots like a beast!!!

    Accuracy is at max with this gun...

    I shot a friend from a good 100 yards away, we were in a battle

    and he has a gun that shoots 435fps, it is supposedly better than this gun, but

    we were a match for each other and the bbs were passing us by - still in the

    air, only inches to a foot away from our heads... I finally caught him when he was


    The safety is click-able...

    The mag is solid and with minimal wiggle room...

    The stock slides out and is solid for being plastic!!! - ABS by the way...

    and the battery compartment is easy to get to and modify...

    Nothing about this gun is cheap!!!! even the plastic parts are Grade A ABS and

    only include the top sight, the foregrip, the handle, and the outer stock -

    the inner stock has a metal bar that keeps it in line!!!

    This gun is meant for upgrades, so break out your wallet!!!!

    KWA is the best Airsoft equipment you can get!!!!

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    Reviewer: Tbrown613
    Rank: LTC
    Location: manahawkin, NJ
    read all my reviews
    7 out of 15 people rated the following review helpful:

    3 out of 5- ok

    Product Information:
    Alright, so I bought this gun about half a year ago and have used it in several games. It is a very effective and fun gun, however, it is not quite worth the money. The reason that so many buy these is due to their high fps and sturdy gear boxes, allowing the use of li-po batteries. However, this gun often fires too hot for many ranges, in addition to the fact that it is difficult to upgrade. For instance, the hop-up that came with mine never worked properly; it is always on. Should you disassemble the barrel, you could see that even in the lowest position, the hop-up is still sticking down. Normally this would not be a problem, however, the gearbox has a special little nub on top of where it links to the hop-up, meaning that only KWA hop-ups will work in this gun. Furthermore, without using a li-po, the rate of fire is rather slow, by comparison to such models as G&Gs M4, which fires faster, is trademarked and costs less money.

    fun to shoot

    hits too hard for some ranges
    hard to upgrade
    li-po is expensive (battery, sack for battery, charger, monitor for battery to ensure that it is not run down too low)
    other brands which have been in the business for longer make better M4s
    many other guns can take li-po DO NOT MAKE YOUR DECISION BASED ON LI-PO CAPABILITIES, Echo 1 guns can take li-po as well (would not recommend buying one though, just an example)

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    (Listed above are the first 10 rated most helpful reviews for this item)

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