SIG516: Sig Sauer enters the AR-15 market!

You saw it here first! I had no idea that Sig Sauer were making AR-15 / M16 rifles but my DSEi spy spotted this prototype SIG516 1 PDW at the DSEi 09 expo. It features a 7″ barrel, putting it firmly in the PDW class, and chambers the 5.56mm NATO.

The SIG 516
Markings indicate manufacture at the Sig Sauer plant in Exeter, NH, USA

I do not know if Sig plan on a civilian carbine version. If they did it would compete directly with their Sig 550 line of full length and short barreled rifles.

UPDATE: jcmiller points out that the lower receiver is semi-automatic. A production PDW would have to be fully automatic. Maybe Sig are thinking of civilian sales.


The SIG516 Tactical Rifle line has three different models:

  • SIG516 PDW : 7″ barrel. A personal defense weapon (pictured above).
  • SIG516 CQB : 10″ barrel. A Colt M4 Commando equvelent.
  • SIG516 BASELINE CARBINE : 14.5″ barrel. A M4 Carbine equvelent.
  • SIG516 Patrol. 16″ barrel.
  • SIG516 Tactical Marksman: 16″ barrel A squad level sniper / designated marksmen rifle.
  • SIG516 Precision Marksman: 20″ barrel. Possibly a true sniper rifle, or designated marksmen rifle.

They are all piston operated and feature an adjustable gas regulator like the Ruger SR-556.

Caliber 5.56mm NATO
Fire modes single shot, 3 round burst and fully automatic (except marksmen models which are semi only)
Controls Ambidextrous
Gas system piston system with 3 or 4 position gas regulator
Upper Receiver Flat top with picatinny rail
Lower Receiver forged 7075-T6 aluminum
Trigger Milspec for all models except the Marksmen which have 2-stage match trigger
Capacity Takes standard AR-15 magazines
Finish black hard coat finish
Barrel chrome lined, cold hammer forged, nitrate finish
Barrel Twist 1:7″ right hand
Stock collapsible SOPMOD buttstock
Weight 6 lbs. (PDW) – 7.28 lbs (Patrol) – 8 lbs (Precision Marksman)
Rails Free floating aluminum alloy M1913 picatinny quad rails
Sights flip-up BUIS (backup iron sights)
Magazine Ships with 30 round AR-15 magazine. Marksmen models ship with 10 or 20 round magazine.
Other Features 0.5x28TPI threaded muzzle
MSRP (Price) not known

Upper receiver assemblies will be sold. Just before anyone gets their hopes up, while it is likely that Sig will sell civilians models, this has not been confirmed.

Big thank you to Lusaka for the information and photos.

  1. SIG 516 as in M16 … get it? 

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.


  • Vak

    I honestly hope this Sig-AR will feature a modification of the gas piston they use on their other carabines.

  • AB

    Somewhere on a gunrange, someone will have two of these without the stocks and will happily dual-weild them shooting targets with a gleam in their eye.

  • Hyperprapor

    Cool. Could anyone post alot photos from expo? May be there is something interesting?

    • Hyperprapor, more new and interesting guns from the expo will be posted tomorrow.

  • Hyperprapor

    Thanx, Steve. This will be interesting.

  • Matt Groom

    Another one bites the dust.

  • SpudGun

    There seem to be a lot of manufacturers pumping out ‘M4-geries’ at the moment – Remington, Ruger, Sig – with an eye towards military and LE sales.

    Is there some sort of Government programme that we’re not aware of?

  • jcmiller

    Considering that the receiver is marked safe and semi only (no third position), I suspect that a commercial release is very likely.

    • jcmiller, ah! I did not spot that!

  • They all see there is a demand for the black rifles. Yet another OLL that would be able to be bought legally here in CA to get past the AW ban.

  • SpudGun

    Thanks for the info Steve. I’m also wondering with the recent ‘regime’ changes in certain parts of the world and the re-equpping of these forces with an AR-15 style weapon might also be a factor?

    Though I’ve shot a few AR-15 variants in my time, I do have a ‘noob’ question for the AR-15 affeciandos out there – Why do most carbine length (16″) barrels thin down in the middle?

    By this, I mean if you look at the barrel for a Ruger 556 and compare it to a Colt M4, the Ruger barrel is one long continous piece, but the Colt barrel seems to dip in the middle and then thicken out again. (I hope my description make sense.)

    Is there an engineering or tactical reason behind this? Maybe to do with D.I.? If anyone knows, please enlighten me.

  • There was a 5.56mm PDW evaluation a while back. Back in August 2008, TACOM solicited five each of the HK G36C, HK416, SIG Commando, Bushmaster PDW, and Kel-Tec SU16D9. Purchase orders were then awarded over the following months. The weapons were to be delivered to Aberdeen Test Center.

  • Moi

    Now that chambered for 9mm, is something I could get excited about.

  • jdun1911


    You’re right everybody wants an AR15.

    The Sig 556 as we all know is a complete market failure. There was so much hype on the rifle that people sold their AR15 to buy it. One year later these people sold their Sig 556 to get back their AR15.

    When you’re dealing with civilians sells, customization rules all. The only auto loader rifle that has nearly as much third party support is the Ruger 10/22 and they sell very well.

    The AR15 is the past, present, and future of small arms. I do not see it being replace anytime soon.

  • englishfil

    My own DSEi experience: I had hands on with this and Sabre Defence’s 6″ barreled PDW which is similar in appearance (magwell grip vs mini vertical grip). I believe the Sabre model _is_ an entry in the British Army carbine comp. Both are very nice, well engineered weapons – Sabre is British!
    HK was showing a prototype 9″ barrel HK416 with a sliding stock similar to MP5 retractable (i.e. rod down either side of receiver). Superb HK German engineering BUT it felt significantly, maybe too much, heavier than either of the first two.
    The SIG and HK are both piston models – I think the Sabre is direct gas – probably no big issue with a PDW because it is less likely to live rough in the field. Knowing Sabre they could do a piston version if you had a compelling contract on offer.
    As a huge fan of short longs I would not hesitate carrying any of them for work purposes if I still had the job – heck of a lot more punch than an MP5K plus I have the M16 pretty sorted in muscle memory. Of course ammo choice becomes more important in shorties – have you seen the price of Mk 262 Mod 1?

  • jdun1911


    The thinning in the middle is to mount the grenade launcher. It also cut down on the weight of the barrel.

  • englishfil: Thank you! I had totally forgotten about the MOD’s “Close Quarter Lethality” (CQL) solicitation from May of this year.

    Expressions of interest are sought from companies wishing to be considered for the provision of qty 300 5.56mm Close Quarter Lethality. The weapon system comprises the weapons and associated ancilliaries. A Modified OFF The Shelf (MOTS) procurement is envisaged. the following Key User Requirements (KURs) must be met by any system proposed for this requirement. The KURs are:
    1) The user requires a rifle capable of delivering an incapacitating effect in an unarmoured human target at 200m range.
    2) The user shall be provided with a rifle that can be brought to bear in confined spaces, overall length (with butt folded or retracted) no more thna 560mm with an objective overall length of 500mm.
    3) The user shall be provided with a rifle with a folding or extendable butt.
    4) The user shall be provided with a rifle that can be fired and operated from either the right or left shoulder.
    5) The user shall be provided with a rifle that can fit the in-service SureFire flash hider via a threaded barrel end.
    6) The user shall be provided with a removable NVH-compatible, 4MOA mini red dot/holographic CQB sight, fitted via a Mil Std 1913 Picatinny or STANAG 4694 NATO Accessory Rail interface.
    7) The user shall be provided with a rifle capable of firing all UK in-service 5.56 x 45mm ammunition natures.
    8 ) The user shall be provided with a rifle that is not degraded by prolonged exposure to a salt fog environment.
    9) The user requires that the weapon is Safe and Suitable for Service (S3).
    100 The user requires that the weapon must not contravene any aspect of the Geneva Convention, Hague Protocol or International Humanitarian Law.
    11) The user requires that the weapon is safe in storage, transport, use, maintenance and disposal.
    12) The user must be able to fire the system in the following operating environments as defined in DEFSTAN 00-35 (A1-3, B1-3, C1-2, M1-2)

  • SpudGun

    Thanks jdun 1911. I suppose with the rail mounted version becoming the norm, it’s not an absolute necessisty anymore.

  • Noah

    Wow. I had figured that SIG was selling all of the 556s that they could make, I’m suprised by this. I guess it’s true, everyone wants an AR.

  • reed

    @ jdun1911:

    I don’t see any indication that the 556 was a failure. Yeah, they were stupid not to make the rifle that everyone wanted (i.e., SG 551), that was already established, but the 556 already has plenty of accessories coming out for it. The only consistent complaint I’ve seen about the rifle is that the SIG skimped on the furniture.

  • jdun1911


    It’s a market failure. If the Sig 556 were a huge success they wouldn’t be coming out with the 516 would they?

    The Sig 556 has the stigma of being the bastard child of the AR and AK. If Sig had put a folding stock instead of the typical M4 version, I think the outcome might be different. Bad overall marketing IMO.

  • CS

    Great news. I love Swiss Arms/SIG rifles. Amazing quality.

    Here in Canada we get the SG550 and a variety of flavors down to the CQB.

    I have a:
    Swiss Arms SG 550 (20.7″ barrel with 1:7 twist)
    Swiss Arms CQB (8.9″ barrel)

    I absolutely love their reliable piston system and the Swiss Arm guns are insanely reliable. Never had a single issue ever with about 9,000 rounds in the last year.

    I thought you might find the tests performed on a Swiss Arms SG 550 interesting

    Great blog, I am a daily visitor.


  • Nick

    Sig has offically died. They were on their deathbed when they started making 1911’s.

    They should just take the “SIG” out of their name and leave it “USA”.

    Keep the real “SIG” production in Germany.

  • CS

    All my Swiss Arms are made in Switzerland. A few SIG pistols are German, never bought any US made SIGs.

  • Wray

    The SIG556 is an amazing weapon-system. I can get .25-.50 MOA out to 300yrds with my handloads, and after burning through 90 Wolfe rounds as fast as I could, I could comfortably hold the bolt in my hand. The 1-7″ twist is kinda fast, but for heavier hunting loads it stabilizes them wonderfully. And it shoots great after submersion in water with a variety of rounds mixed in a magazine.

    I think that the charging lever needs to be re-thought (in terms of the angle it portrudes), and the back-up rear sight is as flimsy as they come. and it would be better if they sold it without polymer. I hate too much polymer on a rifle, especially a polymer rail system-WTF?. But it is by no means a failure. Throw an EOTech on there and take it to war!

    In regards to the 516, I would like to own one, should it prove to be reliable. After playing around with M16’s and M4’s for so long, I’ve just lost interest and respect for gas impingment.

  • racine

    Sig had the right idea for the US market but follow through was sloppy. I believe the tolerances were not to the same as the 550/51 as far as the barrel goes and they left out the stock rear sight in place of a flimsy flip up and cheap red dot. The thing packs as much as an FN para empty. All this for the cost of an FN FAL. I lost interest in this piston drive and will wait to consider the SW M&P PS vs. another lightweight model. If they bring out a model called ‘classic’ then maybe they ought to have near identical furniture and features.

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  • Counsel

    Have a SIG P239 in .40, and I have yet to have any failure. Yes, made in the USA.

  • slavy77

    I read this blog a lot and whenever SIG comes up it seems like there is a lot of negativity towards US made. I’m just getting into hand guns and I’m wondering why so many people are against US built Sigs?

    just wondering.

  • Price of 556 just purchased 9/1/10 was $1700. Included special sigh and hard case. nice weapon.

  • hifiho

    Just bought a 516 Patrol today for $1329 (local dealer). No iron sights. Cheesy Sig-branded red dot, hard case, cleaning kit, and an aluminum 30 rd. magazine. I’ve owned the 556 for a little over a year. I probably won’t make it out to the range ’til after Christmas. Rifle feels good in the hand, and weighs much less than my pimped-out 556. I hope to get a decent scope installed before range day.

  • bee

    I have a Sig 516 patrol & a Sig 522 swat. I haven’t have any issues at all with any of them. Just yesterday i shot 200rds through the 516 with out any problems and shot over 300rds with the 522.
    From my experience:
    Sig 522:
    Shot over 2000rds and had only about 5 misfires 3 of them due to bulk ammo. cleaning is done in 10 mins. It has a Tasco red dot with a angled Magpul foregrip. Its my practice plinker =). plus it is great on the pocket. 500rds for $20 you cant beat that. All in all its a great gun don’t have any issues.
    Sig 516:
    Shot only 500rds. still breaking it in but its been a beast. i put the Bushnell trophy 1x32mm red/green dot in support to the “IRON SIGHTS” that came with the gun. I guess Sig got everyone’s feedback about there red dot and fixed that issue. Kudos to Sig’s PR. i was about to get Troy’s front/rear flip up sights anyways if it did come with the red dot. Over all very impressed.

    FYI… if i didn’t get the 516 i was going to get the DDm4 V5. either way i chose would think i would of been happy either way i went. They both great “USER” reviews many months of research.

  • Sig sauer did a great job again in providing a great flaws of guns in the market. And I’m sure a lot will love to purchase this product of them (Sig 516). Will look forward for more innovative guns in the future. [ firing pin journal dot com ]