I’ve been wrestling with my 556 and an ideal load for its 1:7 twist barrel. It shoots very well with 77 grain bullets but it’s like throwing stones with 55 grain ball… which I expected, but whoa. It makes an AK’s accuracy look good. I have used Varget, RL-15 and 4320 at moderate to high volocity range. The rifle will shoot 55 grain boat tail hollow points about as well as anything else. Generally I get a 3" group at 100 yards. I have three AR’s that all shoot better but this SIG thing is about as tough as nails and shucks an empty about a king’s mile. Anyway, do any M-4 people have any experience with this rifle to share?
Not made to the same high standards as the 550 line.
+1, immediately exchanged the one I bought for a Colt 6920.
I shot the SIG this morning and got some great groups at 50 and 100 yards. They ran in the 3/4" at 50 and 1.25" at 100. Virgin cases make all the difference, but it’s the 77 grain Nosler H.P. that is best in this carbine. IMR 4320 and RL-15 work well. I shot 60gr., 63 gr. and 69 gr too. All grouiped the same at 50-- under an inch, barely. I had a good bench rest, no wind, no distractions. I put a home made accuwedge in it too. Now she’s shooting! That being said, my AR flat top Armalite/ Bushmaster hybrid shot handloaded 55 BTHPs into 3/4" at 100 yards and it has a less powerful scope than the SIG. I have to say that the AR is basically a more accurate system. The SIG folks were thinking about sand in IRAQ getting in the action when they came up with their design. I would pick the SIG if I had the choice in combat, but I’ll still shoot DCM with an AR. I would place a very high standard of production on this SIG 556. It is very well made but the break open type action does need a wedge… just like ARs do. It has a good but not a great trigger as well.
Glad you like your rifle. However, I’m not so sure SIG was thinking of sand in Iraq when they designed this rifle. In fact, Sigarms didn’t come up with the action. The action was borrowed from the Swiss Arms 550 series of weapons developed in the late 1980’s. At that time, they wanted a 5.56 weapon so they joined together Kalashnikov and FAL features to come up with the SIG 550, which later spawned the 551 and 552.
All the USA division of SIG did was come up with that lower and crazy stock set and call it a SIG 556. They had nothing to do with the design of the action. If they did, it probably wouldn’t work so well…
Scott,
Have you had a chance to see the 556’s yet?
Very well stated and very accurate.
I don’t own a 556 and have never fired one but just about every 556 owner says the same exact thing. I love it ,It shoots great followed by where can I get swiss hand guards , swiss folder , diopter sights or something better then the ones Sig offers.
They all seem to buy it and then try to make it into the Carbine they really want... the Swiss 55x.
I'm not bashing just an observation.
The only “sand” that the 556 is going to see is if the owner happens to have some in the backyard. 
This is not a combat rifle, it is a civilian sporting rifle. And it based on a design from 30 years ago.
Must not own any ARs, or consider them for serious purposes, eh???
The point was that the rifle was not designed for the sands of Iraq.
I have a 556 and it compares favorably to my M4gery and FS2000. I have gotten excellent accuracy from mine, with ~1 inch groups with a x3 power aimpoint magnifier. I run mine with an Aimpoint on a Larue cantilever and an X200 on the forend. I have no interest in sidefolders or changing out the handguard. I have been running a sully on my M4 and am probably going to dump the M4 stock on my Sig for a sully. This is just my thing, since I detest adjustable stocks (well, the ones I have experience with). The forend supplied by SIG is quite sturdy, much more rigid than the orginal 550 units, and it allows me to mount a light without much fanfare.
I think the 556 is a winner. Unfortunately, aesthetics are a big part of gun sales, and the SIG is a bit ugly. Most of beauty is just what folks are used to/expecting and the 556 just doesn’t have the lines/perceived lines of the 550s. Now, if you are a function over form type, the 556 may appeal to you a bit more. The mag conversion and allowing it to use AR stocks were probably good ideas–but only if SIG was looking towards eventual police and or military sales. Since I haven’t seen any evidence that SIG is looking into those markets, I think it was clearly a mistake to tinker with the design.
That said, I will never get rid of my 556. It is an excellent, accurate and stone-cold reliable rifle that combines the robustness of the AK action with many of the ergonomic features of the AR.
I own alot of ARs, 9 to be exact, i was looking for something different to tinker with, and i was looking into piston Ars, when i came across this at a gunshow, at the time i knew nothing about the Sig556, and the price seemed right at $1089 OTD, and it had a piston, when i got it home i started to take it apart and see what makes it tic…
The more i got into it the more i liked it, and it has become a favorite rifle of mine…
That is nice! Do you have any pics of it with a 30 rounder and no bipod? I hope the .308 is announced at SHOT. That will really be interesting.
I said earlier that the SIG designers were thinking about Iraqi sand when they designed the 556 rifle… what I meant was that they had to be thinking about world wide sales and their piston design is waaaayyyy more reliable than a direct gas action in adverse climates such as in the Middle East… where all the fighting is… I wonder if the SIG might be a replacement for the M-4. It seems a better rifle than the SL8. I wonder how it compares to the HK gas piston AR. I also wonder how many e-mails that last statement will get. I’m amazed at how excited people get about simple personal opinions.
Weapon,
Thanks for the pic. Looks great.
The 556 has attracted a small but extremely vocal band of detractors. Most of the people who have actually shot and/or purchased one seem fairly happy though. It had a few teething problems, mostly fairly minor finishing issues. Heck, everything has had problems, especially in the early guns. The M4 had its oddness. The FS2000 had the weird firing pin issue…
As far as the SL8, I would take the 556 any day. Not because the SL8 is bad, but because or government has seen fit to cripple imported guns. Now, when the SCAR and 416 hit the market I will probably be getting one of each for my safe!
What i like about the piston on the Sig, is that its enclosed in a tube and has several drain/debris holes, plus 2 postion gas, normal and very dirty… The bolt has no gas rings, no cam pin, one giant locking lug, no buffer, a trigger that has to be felt to be believed, ambi safety, 1/7 twist hammer forged barrel, AR mags, i just installed a FSC556 on it and now it doesn’t move off the targe at all… Am i going to sell my ARs?, hell no, i love them, but just as i was around when they first came out and saw the great strides they made, I glad i’m still around to try the Sig556 at its infancy…
The Sig 556 has come a long way since the 1st rifles rolled off the line and I think more people would have warmed up to them if Sig didn’t shit the bed out of the gate.The QC issues on the early guns combined with dealers charging 500 bucks or more over MSRP just gave the 556 a black eye.
Anyone who owns one seems to be happy so there must be something to it.
I own 2 gas piston carbines that I think do a little more so to each his own.
Someone on the sigforum posted a rumor there would be a “classic” model forthcoming, to be seen at the shot show. This generated about one and a half pages of joyful praise. Then the guy posts that his rep misspoke, and there would be no alterations to the current rifles.
So, I called SIG and customer service informed me there are in fact no plans for any changes to the sights or furniture.
Fairly disappointing.
There were two motivating factors for the furniture and appearance of the 556:
[ul][li] The broader market has embraced the M4 (big surprise to the folks on this forum, I know) and so a gun that looks like an M4 is likely to be more easily accepted by the 99% that don’t really know much about guns, and Swiss-made assault rifles in particular.[/li][li] Since the Swiss-made 550-series rifles are specifically listed as “non-sporting” by ATF, the company was concerned that making an exact look-alike would run afoul of regulatory issues or at the very least poke a bee’s nest at ATF (ATF being a very important federal customer of SIG’s).[/li][/ul]
There is nothing preventing an aftermarket parts manufacturer from creating the necessary parts to make a 556 look like a 551 (more or less). At this point, I don’t see nearly enough people clamoring for those features to justify the tooling necessary. Like all the people who want a 10mm (insert favorite brand here) pistol, a very loud group of twelve people is still just twelve people. 