SiG 556 vs. ??

[epete]

Hello, I'm new to this forum. I am in the market for a piston operated rifle, does anyone have first hand experience with a Sig 556? How would it compare with some of the piston operated AR's, such as POF or Leitner-Wise? I've scoured the internet and come up with very little (useful) information. Thanks!

[fivepointoh]

check out ARFCOM in the link below as they have plenty of reviews about the SIG but w/ that said I would go w/ a Rob Arm XCR.

Here's the link to click on to see all the topics in the General Firearms Discussion.

http://www.ar15.com/forums/forum.html?b=6&f=2



Now a guy just did a somewhat formal and very informational thread comparison between the XCR, 556, and L-W SRT and here is what he had to say.

http://www.ar15.com/forums/topic.html?b=6&f=2&t=216872




Here is another comparison between the XCR and 556


http://www.ar15.com/forums/topic.html?b=6&f=2&t=217569



Hope this helps some.

[JoshNC]

I love my 556. I converted it to 551-like configuration using a Swiss 551 semiauto lower, front handguard, and gasblock.

Here (http://m4carbine.net/showthread.php?t=3789) is the link to my review and pictures.

[epete]

Thanks! That was exactly what I was looking for. I had forgotten the XCR, this does not make my decision any easier.

[PalmerB]

Hello, I'm new to this forum. I am in the market for a piston operated rifle, does anyone have first hand experience with a Sig 556? How would it compare with some of the piston operated AR's, such as POF or Leitner-Wise? I've scoured the internet and come up with very little (useful) information. Thanks!

I bought the 556, and I still prefer my AR (non-piston). My review from the Sigforum:

The Sig 556 in review

Part one- Buying

I had a choice between a Sig 556, the Robinson Armament XCR and an AR-15. The Sig was $1295, the Robinson Armament $1500 and AR’s vary in prices, but it is about $1,000 for a decent one off the rack. I bought the Sig because I already have an AR, and because of Robinson Armament’s history with what I consider unfulfilling and relative abandonment of the M96.

Upgrades for the Sig 556 included the following: Magpul CTR stock with riser ($120) and flip up back up iron sights ($250), I had an extra receiver extension for the CTR stock, but if you don’t have one ($40).

I use rails for a few things:

1. mounting lights
2. Mounting a bipod
3. Free floating the barrel
4. Placing a sling without putting pressure on the barrel. (How the heck did we peg the 500 meter target routinely with a military loop sling, I am not sure).


I do not know if floating a piston barrel assembly will improve accuracy or not, but on a direct impingement AR it works.

Part two – cleaning

Years of experience with the AR-15/ M-16 have resulted in efficient, quick and purposeful disassembly, cleaning and reassembly.

I would say the two are even in this point, except cleaning the buffer spring in the AR is easier than cleaning the piston and spring in the Sig.

Only minor stressors with the 556 are replacing the handle for the bolt during reassembly and disassembly/ reassembly of the 556 firing pin. The AR-15 assembles easily.

Part 3 – Design

I don’t mind the that the Sig 556 came with the funky stock. I figure it is like plastic Glock sights, they use cheap ones because they know must of us will replace them anyways. Same with this stock.

The Sig has a rubber like seal that moves around the charging handle when the bolt is pulled. This may eventually wear. The AR-15 has an ejection port cover that flips open when the weapon is fired, but it is also my experience that this doesn’t form a very tight seal either. The Sig 556 is heavy.

The AR-15 has the charging handle in the rear. South paw/ right hand debate aside (especially since I have read about right handed shooters using left handed rifles because they feel it is easier to operate the bolt), the problem with a side charging handle is that your hand may rub on some wide base optics like the Eotech.

The AR-15 has a chrome lined barrel. The Sig 556 is not. Sig feels it is not needed. The 556 did come with a 1/7 twist barrel, but so do some AR’s. The Sig did have a nice 1/2x28 thread job with a good shoulder.

The Sig 556 does have one of the nicest factory triggers on a semi-auto rifle. In comparison, a good two-stage trigger like the Rock River begins at about $100.

The Sig loses big time points on the grip. This is the greatest oversight in the design, is not making a grip that mates evenly with the trigger guard. I hope an aftermarket grip comes out soon.

The AR-15 uses an ejector in the bolt and a spring to push the ejector. The Sig 556 has a fixed ejector and when the cartridge is pulled back by the bolt it strikes the ejector. I have never had a problem (Knock on wood) with an AR-15 ejector failing, but this is a notable difference in design.

Part 4 – shooting

The Sig 556 is heavy, especially in comparison to a little SBR AR-15. It shot flawlessly without error. I haven’t been able to shoot more than a few hundred at this time, but I’ll defer to the Sig Arms rep who told me they have shot 40,000 through one without incident.

The Sig 556 sounded louder suppressed than the AR-15 with the same suppressor. Our meter wasn’t working well that day, and we’ll need to try another to bring specific decibel numbers.

The AR-15 has also shot flawlessly. We have done some durability tests with it, buying a new one and shooting over 1,000 cartridges through it without cleaning or lubing. I took one to two local back to back shoots with a suppressor on it and encouraged everyone to dump everything they had from Wolf to XM-193 through it. The only error experienced was the magazine catch became stuck open from a large chunk of carbon, and non Magpul followers would gum up in the magazines.

I consider a Magpul follower to be the greatest $2 upgrade to either rifle. The level action of the design improved feeding. Great design.

The Sig shot ½ as precise as the AR-15. I attribute this to a few things:

1. I have been shooting AR’s for years and I learned in the military.
2. I had an aimpoint on the AR and an Eotech on the Sig556, I normally shoot the aimpoint
3. The AR-15, although an SBR, had a free floated barrel.

Part 5 – recommendation

I consider the 556 a good rifle, but if it comes down to only having an AR with optics, or buying a 556 I would go with the AR-15 easily. If you want a Sig 556 because you have always wanted one of the Sig 550 series rifles, do it. It is a nice rifle. I won’t be selling mine.

I have also lost interest in piston design AR-15’s, especially when you can buy a 556 rifle for about the price of an AR-15 piston upper.

For the Troy sight, I had to machine and recoat the posterior section of the rail a little to fold it down as far as it would go and not have it rest at the end of the rail. AN AR-15 receiver is narrow at the back and does not have this problem with the Troy sight.

[TOrrock]

Palmer, thanks for your review.

I have an opportunity to buy one, the dealership I used to work for got one in and called me yesterday.

I swung by today to take a look. My thoughts about the grip (what the hell were they thinking/who the hell implimented that?!) and balance echo your experience.

I'd love to have a pre-89 SIG 550, but I don't think I'll ever get one.

If SIG come out with a side folder thats similar to the original rifle for the 556, I might have to jump.

It won't do anything my Colt 6920 won't, but it is different, and it does have high CDI factor going for it.

[PalmerB]

I only have it to have it.

I have experimented putting a scope on it. I will probably put a lower power 30mm tube scope in a Larue mount or a Acog and use it with a Yankee Hill (Harris) Bipod adapter + Harris Bipod as a SPR.

I have even tried selling it to a few friends who wanted to buy one, but because they are friends, I pull out an AR-15 and explain to them why I like the AR15 better. Then they end up buying an AR-15 and I still have the Sig 556.

Another gentleman I talked to has the same opinion, but he recommended that I just keep it to keep it as a possible investment.

So there it is.

[C4IGrant]

Hello, I'm new to this forum. I am in the market for a piston operated rifle, does anyone have first hand experience with a Sig 556? How would it compare with some of the piston operated AR's, such as POF or Leitner-Wise? I've scoured the internet and come up with very little (useful) information. Thanks!


I wouldn't dig a hole with the SIG 556 personally. The only gas piston uppers I would even consider are POF, HK and the Magpul Masada (when it comes out). Truth be told, I am not really a gas piston fan, but do believe that they have their place.



C4

[awmp]

good info, I was looking at a 556 and I have heard so many issues with just zeroing in the weapon I had put it off, I think I'm going to wait a little longer for my purchase

[Ed L.]

I love my 556. I converted it to 551-like configuration using a Swiss 551 semiauto lower, front handguard, and gasblock.

Here (http://http://m4carbine.net/showthread.php?t=3789) is the link to my review and pictures.

Nice looking gun, but you have an extra http in your link so it comes up as broken.

Below is a link to the pics and thread. As someone in that thread wrote, this is the gun that Sig should have brought out. The Sig556 does nothing for me.

http://m4carbine.net/showthread.php?t=3789

[FN in MT]

http://i66.photobucket.com/albums/h274/montanaguy375/556upgrade.jpg

Mines an early 556 that came with the awful Star Wars looking stock and forend. As well as a useless HOLO SIGHT. The sight would not hold zero and adjustments were erratic to say the least. I gave it to a friends 12 year old for his new 10/22 Ruger. Unsure how it's worked out for him.

I luckily paid Dealer for mine as a customer had ordered it...backed out...and the Dealer was kind enough to sell it to me for IIRC... $1100?? maybe less.

I knew I could resell if I didn't like it...otherwise even with my love of SIG handguns...I would not have bought it. For the $1600 retail price...I NEVER would have bought iit with the crappy irons and furniture.

I also luckily fell into a proper SIG forend and grip from a friend in Alberta. THAT saved me probably a C note rright there. Then added a Mag-Pul stock and some MidWest Industries BUIS's. The sights and the new furniture REALLY made this into an enjoyable weapon. It finally looked good and had some decent iron sights.

From the get go the trigger was crisp and light. It's remained that way. And the gun ALWAYS was easy to shoot. 1" groups at 50 yds or less were easy with most any 55 fmj ammo. With my 55 and 60 gr soft point handloads its a solid 1" shooter at 100 yds. Seems to be accurate right out too 300+ yds. I've popped prairie dogs out to 300 yds regularly.

I've had zero issues feeding or functioning. Only mags I've used are OD Green Mag-Puls. Both the 20's and 30's have been typical Mag-Pul flawless.

The mag that came with the gun .....when left in the sun on my shooting bench WARPED inward. WTF??? Then when it cooled...it took a set and locked up the spring. It now is a doorstop for my barn door. Worthless POS. I'm sure SIG would have replaced it...but I never tried.

The current offerings of the 556 are FINALLY what SIG should have done from the start...more of a 551 gun.

I've had opportunities to sell mine during the hysteria the past few months on ammo and EBR's. But didn't as in it's current configuration I really like the gun.

But.....I like my LWRC M6A2 much more!

FN in MT

[Heavy Metal]

I handled a factory SBR SIG in a Class Three shop a month ago and I wanted to like it but the location of the safety and mage release being in a place where I could not reach and activate either without shifting my grip definately put it way down from where it would have been if they were as ergonomic as an AR lower.

[The Dumb Gun Collector]

I had one. It was a very nice rifle. I think most of the ergonomic shortcomings are more a matter of what people are used to. A lot of folks put grips on their ARs that move the hand position nearly as far back as the SIG 556 relative to the mag release (Magpul MOE, etc). I don't see it as a particularly big deal. I actually thought the original handguards with the built in rail were a really good idea, but folks wanted the less functional classic handguards or the crazy SWAT rail.

I liked mine a lot, but I sold mine in a massive purge to buy my M16. Would I like to have another one? Absolutely.

If I was at SIG I would focus on trimming the weight of the design with a pencil barrel and narrowing the grip up a bit.

[armakraut]

I have a very early SIG 556. It just runs and runs and runs and runs. Not that heavy if you keep what's on it to a bare minimum. I have a swiss 55X front sight and LPA picatinny shotgun style rear sight on there right now, I'll probably add a surefire and either an aimpoint in a LT150 low mount or an RMR in time.

The XCR was impressive, but I had some ergonomic gripes with it. I didn't like the protruding barrel takedown screw just forward of the magwell, frigging annoying. The left side charging was annoying too with a sling mounted at the rear of the receiver. It was lightweight.

Between the two? SIG.

There is a weight tradeoff with the SIG vs an AR and the only problem I've seen has been a small part on the bolt breaking, but it doesn't seem to be a very prevalent problem considering the number of 556 rifles sold.

Both the XCR and SIG 556 are not picky at all with ammo. They eat 5.56 like the cookie monster eats cookies.

[The Dumb Gun Collector]

After getting a face full of oil with every trigger pull on my HK416--I suspect the SIG is also better for suppressed use (given the lack of a charging handle hole).

[Phazuka]

I chose SIG.

http://i30.photobucket.com/albums/c328/phazuka/pics002.jpg

http://i30.photobucket.com/albums/c328/phazuka/pics004.jpg

[Iraqgunz]

I have been considering getting a SIG pistol and then going the SBR route. Anybody have any thoughts about that?

[the_1iviper]

I have been considering getting a SIG pistol and then going the SBR route. Anybody have any thoughts about that?

i sbr'd a 556 pistol,but my wife has laid claim to it.:D

i've read alot of complaints and what not about the 556's but "hers" has run like a top.i haven't had any of the problems that others have reported with theirs and i have a very early model,serial # under 750.

it's an easy conversion once you have your stamp back.screw in a buffer tube and add a stock or put a folder on it ;)

i still prefer a shorty ar to it but it's nice in that it's similar but different.it's a ton of fun to shoot though for some reason.it's obnoxiously loud,the recoil is harsh,it's pretty heavy,maintenance is more time consuming than an ar but whenever i'm out shooting people gravitate to it,just something about them.

i wouldn't recommend it for any "duty" type work but if your looking for a shooter that's a ton of fun i give it 2 thumbs up :cool:

and that pesky --for pistol use only-- marking cleans up nicely with a little work.
http://img.photobucket.com/albums/v619/1iviper/IMGA2597.jpg

[JoshNC]

i sbr'd a 556 pistol,but my wife has laid claim to it.:D

and that pesky --for pistol use only-- marking cleans up nicely with a little work.
http://img.photobucket.com/albums/v619/1iviper/IMGA2597.jpg



How did you do that? Bondo?

[the_1iviper]

actually, dave at the gun garage did the filling and refinishing when i sent it to orion to have the sbr engraving done.

[Moose-Knuckle]

I made the mistake of thinking that the 556 line was of the same quality as the Swiss Arms rifles. The 556 is a commercial rifle, there is nothing "mil-spec" about it. I have made a personal decision to sell both my Sigs for the simple reason they run proprietary parts that one must obtain from Sig. If I had a bolt go down or lost a spring I need to be able to replace that part with a spare myself. If you research the various gun boards there are plenty of issues with these rifles the latest being carrier wear. I have $3200 in my 556 and 556P for that kind of money these guns should not exhibit the kind of problems they have been having. If you just want something different than everyone else at the range then the 556 should serve its intended purpose but if you are considering it as a personal defense weapon I would look elsewhere.

I bought my first 556 back in '07 when they first came out and still used genuine Swiss internals. I bought it new from a local dealer for $1290. First thing I did was to trash the "fish gill" factory hand guards (they had a broken retainer tab WTF) and replace them with Swiss Arms SG551 hand guards. They were $89 plus shipping from Canada. I then ditched the CAA AR stock for a Mag Pul CTR. Sig gave me the run around on getting me the latest factory grip, the one with the build out that filled in the gap between the grip and trigger guard. I wanted to buy one from them but they wouldn't budge instead they insisted that I ship them my complete rifle and they would change out the grip on mine free of charge. I passed and bought one from a guy off Sigforums. The last thing I have added to the rifle was the Swiss Arms front take down pin. No need for two screw drivers for one pin.

I then bought a 556P with the intention of building an SBR out of it but have left it (NIB) locked in the safe as I have changed my mind.

[RUSKI]

I jumped on the "gas piston" band wagon and bought a SIG556 this summer.

Here is what I learned about the SIG556
It was too heavy once you mount your vfg, light, and optics.
Needed better iron sights ( depending on model you buy )
The stock AR style non folding butt was junk and needed replacing.
The polymer handguard was crap and had too much play.
She was too picky with ammo. Anything under 62gr would not cycle the bolt far enough to chamber the next round. :confused:
Not nearly reliable as an AK.
Not at all modular like the AR.
Parts are too damn expensive.
Field stripping & reassembly is a B.... unless you buy more aftermarket parts.

I can go on and on.

Needless to say 1 month after buying her I sold her.
Im not saying they are all bad. After getting used to AR's and AK's the 556 was like a redheaded bastard child with neither platforms better qualities. Thats just my bad experience, some obviously love theirs. If you are used to AR's just get a fine tuned quality AR and dont worry about the SIG. Same for the AK platform.

Otherwise take a close look at the newer generation XCRs and try to shoot anything your interested in before you buy. Personally besides AK's my buddys XCR is the nicest gas piston rig I have shot ( have yet to try POF, Addex or LWRCI ).

Just my 2 worthless cents.

[OhThatGuy]

I've owned 3 556 rifles and a 556 pistol (now SBR'd). They have all run flawlessly with any kind of ammo I could throw at them. I've owned close to a dozen AK's from cheap century models on up to 3 of Krebs' top notch KTRs. The 556 is as reliable as the AK in my experience. It has WAY better ergos though.

The only real knock against it is that it is a little heavy / a little front biased in the weight dept. But that is due to having the robust operating system and all of that forward weight kills muzzle hop. It is the quickest on follow up shots of 25+ AK/AR/Carbines I've owned.

There are two things you can do to make the forward weight bias a very small issue. One is to swap to the 551 style hand guards which take weight off. And two is to avoid putting and RAS hand guards on it or any crap on the rails you may have up front.

The only rifle I kept when I sold off my collection was the 556 SBR. The rifle I'm likely to add back first when I rebuild my collection will likely be another 556 model. They are solid.

[rocket 442]

i checked out the sig at cabeles 2 years ago & wasn't impressed. last spring at my gunshop the owner showed me his with a CTR & 551 style handguards. had to have one so i put down the cash & waited 14 weeks & sig shipped a classic in its place. the love affair was short live, forend rattled,folding stock was a piece of shit. only improvement was the back up emergency sight. is it a 1500.00 rifle? hell no! more like 1200.00 in the classic configuration. luckily had a friend who wanted it more than me. i'd still like to find one in the older configuration.sold my pet ak & parts to an ar build to fund this mistake. first thing i did when i sold it was to get on gunbroker & buy another ssr-85c2 & more sabre defense parts for another build.

[jar420]

I've owned 3 556 rifles and a 556 pistol (now SBR'd). They have all run flawlessly with any kind of ammo I could throw at them. I've owned close to a dozen AK's from cheap century models on up to 3 of Krebs' top notch KTRs. The 556 is as reliable as the AK in my experience. It has WAY better ergos though.

The only real knock against it is that it is a little heavy / a little front biased in the weight dept. But that is due to having the robust operating system and all of that forward weight kills muzzle hop. It is the quickest on follow up shots of 25+ AK/AR/Carbines I've owned.

There are two things you can do to make the forward weight bias a very small issue. One is to swap to the 551 style hand guards which take weight off. And two is to avoid putting and RAS hand guards on it or any crap on the rails you may have up front.

The only rifle I kept when I sold off my collection was the 556 SBR. The rifle I'm likely to add back first when I rebuild my collection will likely be another 556 model. They are solid.

This is my experience as well. The rifle is rock solid, not perfect but what is? 100% reliable and can take much more neglect than any AR. I was not a believer at first, but the 556 Classic is a great rifle. And as quoted above...keep the junk off the front end and stick with 551 hangguards.

[dwhitehorne]

I didn't look twice at the Sig when it first came out. I got a classic a few months ago and love it. I haven't found any ammo it chokes on. Its as reliable as my Hungarian AK. Weight to me is no more than an Hbar AR. My only complaint is how the brass knocks the finish off the back of the ejection port. David

[Phazuka]

I didn't look twice at the Sig when it first came out. I got a classic a few months ago and love it. I haven't found any ammo it chokes on. Its as reliable as my Hungarian AK. Weight to me is no more than an Hbar AR. My only complaint is how the brass knocks the finish off the back of the ejection port. David

those are just little brass kisses, lol. they come off with some clp.

but seriously you can put a piece of electrical tape there and it won't ding the finish.

[dwhitehorne]

No brass marks on my Sig. It knocks the finish off to bare metal. Most use a strip of velcro, but I think that looks cheesy. I've repainted the spot twice. Easy fix. David