sig 556 r questons


March 6, 2011, 12:35 AM
i just bought a sig 556 r on friday & have a couple questons. first can anybody tell mr what kind of accuracy the 556 r gets? is their anything to watch out for with these 556 series of rifles? for those of you who have had your 556 rifles, how are the holding up? when i finally get to go shooting i will let you guys know what kind of accuracy im getting. one thing i find funny is they come with a sig saur red dot & back up rear sight but it doesn't have a backup front sight, what good would this do? finally i bought this from wackendogs here in the classifieds section and would just like to thank him for such excellent service.

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March 6, 2011, 06:32 AM
hi 1:7 twist will need heavier bullets. I put samson sights on mine...essentially threw away the holo sight it came with - could not get elevation down, replaced the rattle prone stock with a magpul acr...great rifle after that! I bought it due to the should come with a sticker... AK inside!

March 6, 2011, 09:23 AM
I really don't like rock-in mags, but I do like the SiG-556
I've been wondering if the 556R upper will work with a standard 556 lower and the C-Products mags ...

... anyone know?

March 6, 2011, 12:00 PM
hi 1:7 twist will need heavier bullets

I believe the Sig 556r has a 1:9.5 twist, not 1:7. This is the 556 Russian model that fires 7.62x39 we're discussing here.

March 6, 2011, 12:09 PM
Yes, the 556R is 1 twist in 9.5 inches.
I just bought a 556R yesterday, and I expect it will hold up very well. As fro the magazines "rocking" in yes; the weapon was designed to use the standard Soviet AK 47 magazine and that pretty much dictated the design. It's how it works on the AKs and on my WASR-10 and as well, the better AK clones as well. For those used to the AR design (which includes me) it may seem awkward but, hey, 'tis what it is.
As to whether or not the 556R upper would work on the 556 lower, even if the retaining pins are the same distance, I wonder if the feeding pattern of the rifle, inside the receiver, is similar enough so there would be no jams, FTFs or other malfunctions.
To be frank it isn't something I would try simply for the sake of having an AR style magazine.
I do know one thing about the 556R; it won't accept the 75 round drum mags that my WASR-10 will, because the Sig's magwell goes deeper into the weapon.
I have heard that if you use "waffle" mags (plastic with a waffle pattern of raised ribs) then judicious use of a Dremel on those ribs on the upper part of the mag is necessary to make them fit the 556R

March 6, 2011, 01:22 PM
To be frank it isn't something I would try simply for the sake of having an AR style magazine.
I ask because I have a SiG-556 ... and an AR in 7.62x39 which uses the C-Products mags ... but I want the best of both worlds :)

I'm also kind of looking down the road ... my parents left me with a collection of several hundred clocks and another collection of Kewpie's, so I know what its like to have to liquidate valuable collections you have no interest in ... I don't want to "give" them away but I really don't want to mess with them.

I'm only in my mid-50's, and I'll always have a few guns around but I don't want to burden my wife and kids with my collection either.

March 6, 2011, 10:17 PM
Only thing that I will add is that I was having issues with the bolt hanging up on the forward cycle. It was enough that it would actually let the bolt stop if you cycled slowly. Polishing that made a huge difference. (The lower angled portion on the front of the bolt carrier. Mine was a little rough. A friend of mine with a 556 was really rough. Dremel with grinding stone and a light touch, wire brush, and a polishing wheel. 20 minutes, both times.)

I have a 556 in 223 and I can shoot 1 MOA with an Eotech 512 at 100 yards.

I don't know the comparison between the 556r and the 556.

This ( might be a good reference. Especially if you are having some problems with the rifle. There have been some complaints about quality control on the 556, and I don't know if or how those affect the 556r. But I go there to look when I have issues on mine.

March 7, 2011, 10:43 AM
I ask because I have a SiG-556 ... and an AR in 7.62x39 which uses the C-Products mags ...

The C-Products AR 7.62x39 mags would be a huge downward step in reliability over the comblock metal AK mags.

March 8, 2011, 12:21 PM
I have the sig 556 and the sig 556 russian. I will pick up the sig 716 (.308) when they release it this summer. Release delay was changing from original ar10 mags to the sr25/dpms/magpul mags = makes everyone happy.

I have a etoch 552 +3x magnifier on the 556 and I use magpul pmags - never had a issue. I m currently looking into optics for the 556 russian. I use bulgarian military ak mags (30 and 40 rnds) with my saiga conversion and 556r now with no feed problems.

First trip to range with 556r was just to get the feel for it. 556r seems to have less recoil then stadard AK. I will get out to the range this weekend and do some real shooting. I will add a muzzel break (5/8x24 TPI thread pattern) and better optics.

March 8, 2011, 06:56 PM
i have not been able to get mine out to the range yet, what about you guys? i hope to get out this weekend, i am worried about the red dot though, i have read several bad reviews on them from guuys with the 556 sig. i have an aimpoint on a m1a bush rifle, that i might have to borrow. i still can't believe there isn't a front sight and instead they give you a cheap red dot sight. does anyone know if you can put an ace folding stock on these?

March 8, 2011, 10:02 PM

You said that you replaced the factory stock with a magpul acr stock, did it require any adaptor or custom fabrication to attach it? I have heard that the play in the factory stock has been an issue and the first thing I would like to do is replace it with something more solid and comfortable.

If anyone else knows the details of putting an ACR style stock on the 556r please let me know.

@ jeepguy
I remebmer seeing a range review for the 556R testing its accuracy with a few different ammo manufacturers about a month ago. I couldn't find it with a quick search but if/when I do I will post or message you the link.

Edit: here is the link to the review...

March 13, 2011, 09:06 PM
well i was able to get out today to shoot my new 556r rifle. it was a pleasnt 36 & overcast lol my friend & i shot it mostly between 50 - 65 yds. i would say we averaged 2 to 3" standing with open sights. it was the first time i have ever shot with a red dot though. so between getting used to the red dot plus sighting it in i think it has more accuracy potential. the only problem we encountered was a lot of failures to fire. i would say about 20% with wolf poly & maybe 5 - 10% with brown bear. i only had about 40rds of brown bear and 60 to 80rds of wolf. when i looked at the round it had a nice dimple, so im not sure what is going on with it yet. the other thing i did not like was their isn't a bolt hold open, which i really missed. other then those two things overall i thought it was great. im hoping to be able to work throuh the ftf issues and really enjoy this rifle. i will probably get a better red dot sight for it though, along with the iron sights that sig sells. did anybody else have a chance to take theirs out to the range?

March 13, 2011, 11:57 PM
..... i will probably get a better red dot sight for it though, along with the iron sights that sig sells.......

The iron sights I see at the Sig website are the rotary diopter rear with the hooded front sight. They seem cheaper than I remember. But they are for the 556; by that I mean the 5.56mm. caliber version of the weapon, as the diopter is calibrated for that caliber ammo, not 7.62x39.
They will work on the 556R I would guess, but the calibrations won't be correct for the Russian ammo, which is not as flat shooting as the 5.56mm.
If Sig or someone else (like, preferably, Aurora) would come out with a good iron sight for the 556R I would really like to get a set for my 556R.
Which I have not yet had an opportunity to fire .... yet.

March 22, 2011, 02:07 PM
The failures to fire with Wolf seem to be a common theme. I had even more severe problems with mine. Here's a couple of videos.

Overall I was not impressed with the fit, finish or the quality of the parts used in the construction of the rifle. The stocks are nothing short of just plain bad. The red dot sight that it comes with is also of low quality and should be replaced if you plan on doing a lot of shooting.

I returned my rifle to my dealer.

March 22, 2011, 05:12 PM
What a shame. My 556 had to go back for repairs right out of the box. It wouldnt feed rounds. Apparently the mag was hanging too low but they would never admit it. Accuracy on mine is also lacking compared to the cherry picked samples reviewed in several gun article mags.

March 23, 2011, 06:24 PM
strumgewehr i watched your video the other day and then some of your other video's, they were all very good btw. imo these sig 556r's need a stronger hammer spring, a stronger recoil spring, a stock that is ar 15 compatable, & a chrome lined barrel. i can buy the stock adaptor myself & i will if sig can get this to run right. they are now sending me a shipping label. the worst part was that i liked the mini 30 tacticle until i found out about the light firing pin strikes with foreign ammo, so i passed on that idea. i had decided to get an arsenal sgl 21-71 when i saw these rifles in the classifieds here, & decided to get the sig instead. $1100 vs $750 big mistake on my part now im still going to get the arsenal and figure out what to do with this rifle. i like how it handles & the accuracy when it performs right. i think this is a good idea that went bad when the bean counters got a hold of it. which is why you see the cheap but stock, non chrome lined barrel and no front sight.

March 23, 2011, 07:13 PM
This was posted by a user of my Facebook page:

"I got the 556R with the intent of using the steel cased ammo. I took the rifle out today and it shot fine until I got to the wolf ammo. I called Sig and talked to Josh in customer service, he informed me that Sig will void the warranty if steel cased ammo is used and that it will not work in the rifle. Only brass and non-corrosive ammo is to be used in the rifle. i will be selling the rifle due to the fact that I have several cases of the steel ammo and that Sig did not put a disclaimer on the web. Josh made the statement " Its in the owner manual but not on the web" So if you are thinking of buying the Sig 556R you can only use brass ammo."

Another user on the forums confirmed that customer service agents at Sig are now telling folks this on the phone, this time the caller spoke to a service rep named Scott:
OTOH as I was typing this I was on the phone with Sig and spoke with "Scott," and I asked him about this and was told it IS TRUE -- not supposed to be used with steel cased ammo!!

Not good considering steel cased ammo is the defacto standard in 7.62x39 and most people will shoot it. I would say this is a major issue with the rifle.

March 24, 2011, 02:11 AM
I've been shooting mostly Wolf steel case in my Sig 556 and it's been fine. What's up with the 7.62x39 version? That is a definite turn off.

March 24, 2011, 06:38 AM
I've been shooting mostly Wolf steel case in my Sig 556 and it's been fine. What's up with the 7.62x39 version? That is a definite turn off.Yep ...

I can't believe I'm hearing about this on THR ... I'd thought SiGform members would have mentioned this. This is kinda important info and I wish this would have come out sooner. I guess its just another kick in the head for jumping on the bandwagon too soon. I got one off Gunbroker and its sitting down at my FFL waiting to be picked up I guess I'm just bound to be a "beta tester" :fire:

March 24, 2011, 02:11 PM
Man this gun must suck, all reviews I have read are saying the same things you all are. FTFs ,FTEs, poor quality finish, and stock issues. I just want someone to make a viable alternative to the AK that fires 7.62x39. The AR design is nice, but the magazines are the problems.

March 24, 2011, 06:05 PM
i am going to get this looked at by sig & then sell or trade it. i would still own or buy a sig p series pistol but nothing else made by them. this is very disheartening as i was excited about this rifle when i found out about it. i violated my own rule though, never buy anything the first year it comes out, regardless if its a firearm, car, or anything like that. now it comes down to how much money am i going to lose in getting rid of this? i do thank all of you for your responses, jeepguy.

March 25, 2011, 08:04 PM
Thank y'all so much for the follow-ups!

Saved me from a horrible mistake. I really wanted one of these and got an Email from AIM offering them for $1050, really glad I checked back here first!!!

As I've said repeatedly, "aint' much of a gun if steel cased ammo breaks it!" making a 7.63x39 that don't work with steel cased ammo is stupid beyond belief!

SIG seems to be really heading downhill with the GSR, P238 issues, and now this!

just want someone to make a viable alternative to the AK that fires 7.62x39. The AR design is nice, but the magazines are the problems

MGI makes a "modular" AR lower that takes an adapter to use AK mags:

AT $500 its IMHO a bit pricey for a stripped lower, but you could put one together for about the cost of the SIG 556r. I'm investigating this option now. One other is the PTR-32, an HK-93-alike in 7.62x39 that takes AK mags. CDNN sells them for about $850, but I've heard even less about them than the SIG 556r.

March 25, 2011, 09:17 PM
There has been an update by crowepa22 on the original thread at

GOOD NEWS! I just got off the phone with Scott, the head of costumer service, and he inturn talked to the engineers and product development people about this and the gun was tested with the lesser grade ammo, steel, and from Scott " It will not VOID the warranty if steel ammo is used in the 556R. You may find some of the ammo that will and will not work. But it will not void the warranty" I will be keeping the rifle. It seems to funcition with most of the ammo I have used and I will be doing testing to find which one works the best. I will keep everyone informed on which ammo works the best.

June 21, 2011, 04:48 PM
After doing more Googling about the MGI setup I decided against it.

Took a chance on the SIG 556R and have had it out three times, so I thought I post here instead of starting a new thread.

First time out I used the lame red dot that it came with, SIG lists it at $199 on their website, what a joke! I'd much rather it'd had come with the $142 "diopter" sights also listed on their website.

My initial result using the Bulgarian "slabside" metal lined plastic mag it came with was not good, having several bolt over base feed failures and many failure to fire with Golden Tiger ammo, although all the primers appeared well dented. Next I tried a steel comblock mag that has been fine in my Saiga loaded with Wolf FMJ. Perfect function and I was beating up the steel plates as by then I'd got the red dot reasonably well zeroed despite the frustration with the Golden Tiger ammo.

Feeling pretty good I gave a Tapco mag a try, also loaded with Golden Tiger. Again about 10% failure to fire and two bolt over base feed failures.

Next another random comblock steel mag loaded with Wolf JHP, again 30 rounds perfect function.

Finally a steel comblock mag loaded with Golden Tiger. Perfect feed and ejection on the rounds that fired. I picked up the 10 or so "duds" and stuffed them into a steel mag, all fired the second time with no feed or ejection issues.

I cleaned the rifle, especially the firing pin channel, and mounted Midwest Industries SIG 556 flip up front and Magpul flip up rear for BUIS, lost the red dot after using it to get the BUIS in the ballpark, and then mounted a Millet DMS 1-4X scope in a QD mount.

Tried the Bulgarian plastic mag and Tapco mags again loaded with Tula FMJ and took them out after the first bolt over base feed failure, stripped out the rounds and loaded them into a steel comblock mag wich then functioned without issue. I then ran three other steel mags loaded with Brown Bear, Wolf JHP and Tula with 100% function. No failures to fire with these three ammos.

Third time out I just brought only steel mags including a Korean than most folks bad mouth, although they've always worked for me. I had a mag each of Brown Bear, Tula, Wolf JHP, and Golden Tiger. Had 100% function with the Korean mag loaded with Tula, 100% function with the Brown Bear, Three failures to fire with the the Golden Tiger, and this time one failure to fire with the Wolf JHP. Again all went the second time.

Overall I'm very happy with this rifle and have had none of the feed or extraction/ejection issues Sturmgerwher showed in his youTube videos. I'll try the Bulgarian plastic and Tapco mags in my Saiga and if they fail I'll toss them down range and use them as reactive targets :)

Condition were not suitable for any accuracy testing (10-30 MPH wind gusts) but off sand bags at 50 yards, waiting for reasonable calm I got groups with the Tula about half the size I generally get with my Saiga. Next time I can get out on a calm day I'll try a head-to-head with my Saiga, AR 7.62x39 upper, and the SIG 556R.

I'd be hot to try a stronger hammer spring, or do a minor mod to increase the firing pin protrusion a tad like I had to do for my AR 7.62x39.

June 21, 2011, 10:05 PM
I got my Sig 556 and it wouldn't zero, come to find out the barrel wasn't fit to the reciever correctly.
I sent the gun back to Sig after a 3 call circus with the Sig (lack of) Customer Service and sent it back.
I waited and waited and finally got a call from Sig and after a long conversation was offered a 556R. The rifle was a disappointment to say the least.
I traded it for a loss of $700 loss and got an M1A.
I wont buy any Sig produst again that is made in the USA.

June 21, 2011, 11:13 PM
They are great systems for reliability but they shoot crooked. If you like pistons the ticket is and H&K AR or then an average Bushy, Delton, RRA, Colt(more moola) with the adams piston.

June 22, 2011, 06:57 AM
I would research it a bit more before you call it reliable.
Go look at UTube videos linked on this post.
this is pretty much my experiance.

June 22, 2011, 07:02 AM
Thanks Wally ... great review and range tests write-up!

I'd be hot to try a stronger hammer spring, or do a minor mod to increase the firing pin protrusion a tad like I had to do for my AR 7.62x39.
Just curious as to the mod you did on your 7.62x39 AR?


June 22, 2011, 09:17 AM
I bought a 556(not r) right after they came out. Aside from being way too front heavy the bolt failed to strip rounds about 60% of the time so i had to send it in. Has worked fine since but all in all i regret the purchase. The early quad rails move around so can't be used to mount any optics or lasers. I managed to make the bottom rail solid by fitting a bayonet lug that pushes against it but the top rail is still useless. I do like the way the patrol version handles though with the shorter hand rail. All in all though I think the sig 556 is just another reminder how lacking american made sigs are.

June 22, 2011, 08:40 PM
Just curious as to the mod you did on your 7.62x39 AR?

Basically you chuck up the firing pin and take about 0.0005-0.001" off the shoulder that limits the firing pin forward travel, this increases the protrusion a bit.

Use the search I believe the detailed instructions I used were posted here.

June 22, 2011, 09:43 PM
Utube is good but beware of using this as the ultimate driver for any conclusions.

June 22, 2011, 11:01 PM
Utube is good but beware of using this as the ultimate driver for any conclusions.

Obviously he was having a lot of problems that would make me an unhappy camper. The the real question is what did SIG do to remedy the situation? If nothing, then I'd be wary about recommending them, but so far my experience has been good, although SIG needs to ship out a better quality steel mag instead of that commercial Bulgarian plastic mag -- even the Korean ones have worked for me.

June 22, 2011, 11:08 PM
I don't undersand manufacturers. They might have a great product and they go and piss all over with second quality magazines.
They do not even give you an option. Do you want a maintenance preventive pack? A good sturdy magazine upgrade?
They might be able to do for $10 each extra, who knows.... All value added in my mind.
But they try to cut corners instead.

I do know FN bend backwards for LE/ and military and when you retire and have a problem screw you. I had an issue and took them months to literally do nothing. Will never buy from them again.


August 27, 2011, 02:52 PM
If anyone is interested, I've got videos of both the PTR-32 KFM4 and the Sig 556R I've recorded recently, check them out!

PTR-32 KFM4 with Grip-Pod:

I've also got a video of a Sig 556R in 7.62x39mm with Redfield Revolution Optics and Grip-Pod:

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