my thoughts on the Sig 556

General Firearms Other Semi-Automatic Rifles
1

I have been keeping an eye out for something “different” for a while. I have been considering AK47’s. AK74’s, CZ58’s, etc… Basically I wanted something other than an AR15/M4. I have several of those now. Time for something else. So, on an impulse I decided to see what the hype (mostly negative) was surrounding the Sig 556. I agree with 99.99% of the population that the stock and handguard look cheap. However, that is not a problem without a solution. 551 handguards are available as are quality stocks such as the Magpul CTR and VLTOR. In fact, it looks like the 551 handguard shape can be easily obtained by grinding the fins and bottom rail off of the lower handguard with a dremel or belt sander. Still, the upgrade is not necessary to make the gun “functional” as is often claimed.

The rifle is a little nose heavy, but I tend to like 12" handguards on my 16" carbines anyway so the weight actually did not feel out of the ordinary. Also, I think the 551 or modified handguards will help reduce the amount of weight out front. My 556 came with the joke of a rear sight that Sig was humorous enough to include. I have a set of BUIS on order to fix that problem though.

I also observed a commonly mentioned complaint about the mag release. It is farther forward than an AR15’s. Nevertheless, I had no problems activating the mag release. For a point of reference, I wear a medium in most gloves, so I do not have large hands.

To shoot this carbine, I pulled an Aimpoint M3 with 2moa dot off of one of my 14.5" carbines and started trying to sight it in. The more I shot it the more I began to like this gun. I found it to be very quick and the dot on my aimpont seemed to dance around much less after the shot than on my 14.5" AR15. Plus, I was getting more “A” zone hits on reactive steel. The recoil impulse was much slower and different than an AR15/M4. The recoils was not as sharp, if that makes sense.

I have never liked the location of the charging handle on the AR15 platform or the AK47/74 rifles. To me neither platform scores high marks in that category. The forward charging handle like that found on many HK’s and now being introduced on the Masada/ACR have always made more sense to me. So to me the Sig’s charging handle is no worse or any better than that used on the AR15/M4.

The trigger was not impressive the first time I dry fired it in the store. I did not like the creep. However, the pull feels light and is much nicer than any standard trigger on the AR15 or AK47. I found it to be much easier to make accurate hits and shoot faster, accurately with the Sig 556’s trigger than an out of the box AR15.

The safety lever is different than an AR15 and is a little stiff. However, I like it. Not sure if I like it more than the AR15’s, but it is light years better than an AK. I do not have a problem with ambi-lever rubbing either, as in it does not rub.

The fixed ejector absolutely launches brass. The 556 shot empty brass 10 yards at 2:00 every time.

I had no failures with AE223; however, I had a few short strokes with some Wolf 55gr. After a couple short strokes, I changed the gas setting and problem solved. I only shot a total of 200 rounds through this gun as I had others ( one of which is pictured below with the 556) that needed attention and to be sighted in.

I was not really anticipating the release of this carbine. I did not keep track of it prior to its release. I have always thought the Sig 55x series were “cool” guns, but never gave much thought to them other than that. Having said that, I would rather have a Sig 556 than a semi-auto 550/551. The ability to use my Pmags and a CTR is a huge advantage in my opinion. Fixed stocks almost never fit me correctly, and I have no need for a non collapsing folder. I also have no need for another magazine to have to stockpile or pay a premium for.

Sig missed the boat with the cheap looking furniture and lack of sights from the factory; however, the underlying rifle might be a winner. I look forward to obtaining my upgraded sights and furniture as well as getting more rounds down range. I will share my thoughts as I get more time behind this carbine. For now I am rather optimistic.

Edited to add: The rail on the reciever is not canted. Also, the gun is marked Sig Sauer instead of Sig Arms.

2

thanks for the input. I just got a 556 3 weeks ago and have not had a chance to get her to the range yet. I put my Aimpoint M2 on it in a Larue mount which seems to be working out so far. On order for mine is a Viking Tactics padded sling with HK loop since this gun has the loop in the front and a Vltor Emod stock to replace the one that came from Sig…

3

My Sig 556 in its current configuration:

I have about 600 rounds through this gun so far. After removing some of the the thick grease that came on the BCG and lubing the rifle with Slip 2000, I no longer have to turn up the gas with Wolf.

This gun needs to have a high volume shooting sesion, but so far I am impressed.

The sights that came on the rifle are sighted in; however, they are a joke. I have a Samson front sight and a Troy rear in my possession, but I am patiently waiting on the rear sight from Aurora. If this were my only gun or my go to gun the Troy rear and Samson front would have already been installed.

I am in the process of trying to determine the best way to mount a X300 on the 551 handguards. The 551 handguards and the pistol grip will soon be introduced to OD krylon.

4

Some of the neg’s that I’ve heard about the 556 that really bother me are a cast lower receiver and a non-chrome lined barrel. Again I am not 100% certain of the cast part but am pretty certain on the non chrome part. I could probably live with a cast lower but I absolutely require chrome lining on ‘my’ rifles. If I heard today that all 556’s would have chrome lined bbls in the future I would without doubt begin saving for my 556 fund. If they would address this feature I think they would one of the worlds greatest rifles on their hands. Now if they (Sig) would just listen:)

5

Why?

How exactly is the barrel on the Sig 55X series of rifles deficient? How would chome lining make the barrel better?

6

I have always wondered the same thing. Chrome lining is obviously a plus for those who shoot quite a bit in adverse conditions and don’t have the chance to clean/lube much between engagements. I clean/lube my guns after each range outing, so I don’t see the need at all. I was always under the impression that non-chromed barrels had a slight accuracy advantage as well. I have multiple guns with both chromed and non-chromed barrels, and I have never had an issue with corrosion of any kind.

7

“The trigger housing is machined from an aircraft grade aluminum alloy forging with a hard-coat anodized finish…”

8

Thanks for the replies, that makes me feel much better about the lower. The advantages of chrome lining I think are well known. Decrease in corrosion, eaiser cleaning etc. It was one of the key factors to improving the M16 in 'Nam and I feel it was a large part in the AK’s great reputation. It would be no problem as a range gun but I want one I can take to the ‘field’ for extended periods. Like I said earlier, if they begin to offer chrome lining, a 556 would definetly be in my future.:wink:

9

Nice progress.

I remember seeing someone say on another forum (sigforum I think) that some of the AR style handguard adapters work in the 551 handguard holes.

For some reason I recall hearing that original 55X rifles don’t have chrome lining either.

10

Nice rifle.

Were did you locate the 551 hand guards and the pistol grip? Do they just mount right up with no modifications?

11

Thanks, the pistol grip is the one that came on the rifle. I bought the 551 handguards from AZgunrunners. Aurora Industries stocks them also, but has a hard time keeping them in stock. The handguard is a direct replacement. No mods needed. Just as easy to swap out as regular ar15 handguards.

12

I don’t mean to bring this thread back from the dead, but the Sig 556’s barrel is nitrocarburized rather than chrome lined so you’ll have no problems subjecting it to heavy/extended use.

Tspeis

13

I had gathered that from researching here and Sigforum. In a way I have added the 556 to my next rifle list, but it is down the list a bit. Behind the SCAR, ACR most defintely and possibly a couple of other rifles as well. I do like the 556 I just wish it had been a little closer to the 550.

Thanks for the reply, BTW is the nitrocarburized treatment also used on the M60 barrels or other MG’s to stretch barrel life? Seems I had read somewhere it was.

14

Many years ago, when I was a 60 gunner, I attended the 18th Abn Corps Machinegun Leaders course, I was taught the first 6 inches of teh 60 barrel were lined with stellite, the rest was chrome, the barrel also included a heat expansion joint, making it difficult to ruin a barrel by overheating.

The Sig looks nice, unfortunately, my hands must be smaller, because the mag release feels like to far of areach for me. I’ve thought about giving one a try, and see if can be overcome easily, maybe I will.

Bob

15

Not sure on the M60, but for what it’s worth, the FN M249, M240 and HK MG4 barrels are all chrome lined and last pretty damn long! :eek:

Personally, I’m waiting on Sig to release this:

I’m in the same boat as you as this isn’t exactly the first thing on my list. However, I did speak to a rep from Sig today about this. They have a part number for it already and it should be released sometime around August. Only downside is that it’s select fire and only available for agency purchase. The upper will mate with a semi auto 556 lower, so I’ll work on getting the upper. :smiley:

Tspeis

16

Nice rifle, It would probably replace the existing 550’s in the Swiss forces rather than export.

17

Sweet rifle, they keep improving the 556. It is becoming a more attractive rifle all the time. I just read a new article on the SCAR. I’m waiting on the SCAR and the ACR. I belive one of these will be my pick. I think that FNH will hit a home run with the SCAR I just hope Bushmaster does the same with the ACR.

18

Im holding out for the SCAR as well but the SIG556 does look interesting.

Here’s part of a e-mail I got from FN a week ago inquiring about the SCAR rifle’s

We hope to have these in limited quantities after October. Pricing will not be available until September.

6 more months to go :smiley:

19

Any thoughts/oppinions on the Commando version with the side folding stock and green furniture?

20

I know it is beating a dead horse, but why did Sig build these things? Instead of
the STG 90/ 550-2 rifles that would have sold like hotcakes.
The things corporations like Sig/ Colt/ S&W do to shoot themselves in the foot astound me.