First, I am fully aware of the backstory on the 556xi, and all of the promises that were made that Sig failed to deliver on, and then how they dropped support because the MCX came out. No need to delve into that again.

In members personal experiences, were there any issues with the xi models? I just picked one up for what I think is a good price (11.5" pistol version with some HK416 sights on it for $900) but I am wondering how long it will last me if really put to use...since I know replacement parts will be hard to come by.

lost track of the variants but have to say that Sig really STB on the 556 unit. Probably my most favorite unit I own. Feels great in the hand and have had no problems. Just a great unit. Why they did what they did still blows my mind and put a bad taste in my mouth that has never left. Still piss' me off.

quote:

Originally posted by old rugged cross:
lost track of the variants but have to say that Sig really STB on the 556 unit. Probably my most favorite unit I own. Feels great in the hand and have had no problems. Just a great unit. Why they did what they did still blows my mind and put a bad taste in my mouth that has never left. Still piss' me off.

The Xi was the last version they made. Had a 3 position gas setting, was (hypothetically) caliber convertible between 5.56, 7.62x39 and .300 BO, and had interchangeable lowers so you could use AR style or AK style mags. Also the charging handle could be switched to either side.

I have the 7.62x39 version and my only comment is that it doesn’t like old ammo like 80’s Norinco. A number of jams. But it worked fine with more modern ammo like Wolf and Red Army Standard. Had the 5.56 version, but got rid of it because it really wasn’t much different than the pre -Xi 556.

I can't comment on anything other than one in 7.62x39, and it was terrible. Poor accuracy and poor reliability.

I know the 16” Xi’s had issues but I’ve got a pistol Xi in 7.62x39 that I SBR’d and as long as I use synthetic mags I haven’t had any issues with reliability and the accuracy is fairly good depending on what ammo I’m using up to 100yards, it’s also scoped and has a better trigger.
It’s more accurate than my Hungarian AK which I’ve only shot out to 100 yards but it has a 16” barrel and not scoped.

I’ve also bought a couple Xi lowers (trigger groups) on GunBroker because of the ambidextrous safety & mag release for my P556 in 223 and P553 in 223 and reliability has been excellent with them as well, plus they have the SiG logo on the magwell and that’s a nice touch.

Sorry the pictures are kind of old


These are 556 & 553 uppers with Xi lowers & stocks.

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How reliable is the Sig556xi?...how long it will last me if really put to use...since I know replacement parts will be hard to come by.

There's no good reason to force an impractical gun into a pragmatic use-case. The Swiss Sigs are fine rifles; though almost inarguably novelty/collector pieces, when you're considering rifles that would be appropriate in the context of contemporary (American) preparedness.

If you're looking for a gun to "really put to use", the 551/3, 556, and 556xi likely aren't worth investing the time and ammo, and the 556xi ranks last among those.

If you want to shoot it a lot, I say get after it. It probably won't fail. If it does, you will have almost certainly got your $900-worth out of it.

In my efforts to really "put guns to use", I have found myself drifting further and further from the 55X, and investing more into the AR15. Sigs are sweet, and they're why I am a member of this forum, but they aren't a good choice for a contemporary pragmatic rifle, IMO; not so long as the AR is a choice.

When I say the 55X is impractical, when compared to the AR, I mean in terms of support (your primary concern) and size/weight.

We’ve never had any issues with ours. It eats everything, no problems. It will even shoot steel cases with absolutely no issues at all. Every theme we’ve taken it out, ran like a champ. It’s definitely a keeper, at least ours is.

I have had probably four different 5.56 Sig556 rifles, and one 556R (gen2). Like m1009, I never had any issues; all ran flawlessly. Brass, steel, suppressed, etc. One of the 556 rifles I got (sight unseen) was run hard by the previous owner. It had a bent piston rod, broken recoil spring, and broken extractor retaining pin. This was a "patrol" model with a fluted rod and braided spring. I used that experience to inform spare parts opinions.

If I owned a patrol model with the aforementioned recoil assembly, and wanted to "put it to use", I'd try to get a spare recoil assembly or upgrade to the solid rod with flat wire spring. Where the extractor pin is concerned, you're better off just having a spare bolt on hand, as opposed to replacing the pin.

Cocking handle rubber covers, dust covers, and buttstock recoil pads are other wear items, but are not easy to replace (other than cocking handle cover), and aren't critical to operation.

I bought the xi some years back in 5.56mm (16").
Never had any problems but holy smokes it would LAUNCH the ejected brass away like 40ft or so.

I have since cut it down and SBR'd it to 11" and put a suppressor on it.
Still runs like a champ.

I still have my 556xi Classic pistol and it still works great, but it has been a couple of years since I last shot it. I put it away on the furthest backburner because I left the brace on it, but I plan to take it out in our next outdoor shooting fest. I have maybe 600-800 rds through it and never had an issue with it. But yes, it ejects brass with great force, and it is loud as hell, I don't shoot it indoors anymore.