Originally written July 19th, 2011
Barrel & Muzzle Device:
The SIG 551A1 is not a Swiss Arms SG551. Lets get that out of the way first. It is however inspired by the original and most of the parts except barrel are interchangeable. The Swiss government/army has some hang-ups about allowing their proprietary barrel/trunnion system to be copied in the USA. At least that's what I have been told by Colorado Gun Sales (COGS). The 551A1 is a different take on the SIG-556 series. It uses the same gas piston system, bolt/carrier group, sights, and upper receiver. The barrel is about 17" long, cold hammer forged, and with a 1 in 7 twist rate. It has a standard AR15 thread pattern. The original Swiss STGW.90 (military SG550) uses a 1 in 10 twist rate in its barrel to stabilize the 5.6mm GP90 ammunition. Also, the flash hider is physically part of the barrel, not a separate piece. So honestly, for the American shooting public, the 556/551A1's barrel is better for everyone, except the biggest Swiss purists.
The 551A1 comes with a unique muzzle brake/flash hider. It is definitely inspired by the 550 flash hider with large slots and a raised lip behind them. It is a bit long and I am not sure why exactly. It does look a lot nicer than the A2 flash hider that ships on the 556 for sure. I haven't made up my mind if it is worth keeping on the rifle or if it should be replaced with a reproduction 550 flash hider from either COGS or MFI. Both of those companies have quality products and knowledgeable owners. The 551A1 did not come with a bayonet lug, which disappointed me. That said, most of the semi-auto SG550s and SG551s also did not ship from SIG with lugs and installing one is easy. The mount for the lug is under the gas-block so all you need to do is pop the lug in and stake it with a roll pin. Again, both COGS and MFI make reproduction lugs for the 556 series. You can get either an original Swiss style lug or a NATO style. This is one upgrade I think the rifle needs just for the look if nothing else.
Upper & Lower Receivers:
The upper receiver, lower receiver, and gas-block are Swiss grey. The barrel, front sight hood, and receiver rail are black. The bolt and carrier are a matte silver color. Upper receiver is made from steel and lower receiver is made from aluminum. Most of the lower receiver parts are familiar from the 556 Classic including: take-down pins, trigger, bolt release and safety. The one new part is the Swiss style magazine release. Yes, this one uses original 550/551 magazines, and CDNN has brand new 20 round and 30 round magazines to support this product. They aren't cheap, but if you are an H&K owner, their prices will pleasantly surprise you, I think. If you are only used to AR and AK mags, well... they will seem expensive, but hey, they do lock together which is neat.
The rock-in mag well is not nearly as fast to operate as a standard M16/AR15 like on the 556, but hey the point of the 551A1 is to be more like the SG551, so there you go. The rifle uses AR type captured take-down pins, instead of the spring-loaded free pins of the SG55x series. This, to me, is an improvement, but no it's not original, and I know some would have wished them to have the original style. Also, the trigger guard is AR style. It folds down to get out of the way for gloves, instead of to the side like on an original Swiss rifle. I was told they did this to save about $30-$40 cost and to use a more modern manufacturing method. Again, to a shooter this won't matter but to someone wanting a true SG551, it is a little disappointment I'm sure. Safety is ambidextrous and the trigger on the 556 has always impressed me right out of the box. The lower does have the added rear sling swivel, which, no matter who you are, is a good thing.
The upper receiver is standard 556, but grey. It uses the 3 hole rail. Not really much to say about it.
Furniture & Factory Sights:
The buttstock is Swiss 550/551 style. It's either an original or a good copy. It locks up solid in both positions and feels solid. That said, I'm not going to use it as a pogo stick to test just how strong it really is. The handguards and pistol grip are straight from the 556 Classic and honestly could stand to be swapped out for a more authentic Swiss look. The handguards aren't bad but have the usual loose fit because the gas-block doesn't have that internal coating like the originals. The pistol grip is perfectly serviceable with a storage compartment, but again the whole point of the 551A1 was to reproduce the SG551. Seems like Sig Sauer could have easily put original grips on these without effecting costs.
The sights are standard 556 Classic. This means the front is a hooded post and the rear is an adjustable diopter clamped onto a rail that is itself bolted onto the upper receiver. The front sight I don't have a problem with, though I do wish it had the flip-up night sight for the look of it. The rear sight has been called an airsoft part and maybe it is. It's just there. Would I pay money for it? No, but at least they provided something in the rear. The rail also has the standard flip-up popsickle sight under the diopter sights.
Magazines & Gear:
The rifle comes with one 20 round and one 30 round magazine. They are original Swiss mil-spec with couplers. It also comes with a rail tool, rather thick manual and in the usual Sig blue hard case. CDNN has both sizes of magazines available for under $60 each new. I have been unable to find original mag pouches or slings for the 550/551 yet however....I have put an IMI Mini-Uzi/Galil sling on the rifle and it works well for an inexpensive military sling. I have also found the FN FAL mag pouches hold the 20 round magazines perfectly. My Belgian/German pouches hold the mags side-by-side separately well, and my Israeli pouches will even hold the magazines coupled together. I haven't tried yet to find pouches to fit the 30 round magazines, but I bet at least some M16 military pouches will do the job fine.
The SIG SAUER 551A1 is not a Swiss Arms SG551, but is not too far off in terms of operation and parts interchangeability. No, the 551A1 doesn't have all the refinements and some of the little things of the originals. Yes, SIG SAUER has had QC issues in recent years. Yes, the Swiss-made guns are objectively nicer. They also cost three times as much, or would if we could import them. It is illegal to import SG550s and SG551s into the USA and has been since 1989. Just accept that. Even back in the 1980s, originals cost several thousand dollars. In Switzerland today factory new rifles cost between $3,000 and $4,500 depending on model and exchange rate of the week. Pre-ban models in the U.S. now start out at $8,000 and go up from there. COGS has 556, 550 or 551 conversion kits for $2,500 or so. There is a WCA SG551 on Gunbroker at the time of this writing with a starting bid of $3,500 and a buy-now of $4,300. So my point is, you can get a really close copy of an original if you have the money and desire. There is not a cheap way to own a SG550/551 and never ever has been. All those Swiss refinements and hand-fitted parts cost big bucks.
Some have said that SIG USA should import a bastardized sporter version of the SG551 and convert it state side like Arsenal does with the SGL series. They could if Swiss Arms wanted to make such a gun, but it wouldn't be cheap. A basic SGL-21 costs $700 and one with an original style folding stock costs $1,100. If you were to buy the same guns in Russia, if they would be legal to own by civilians which they are not; they would cost around $400 for a basic model and $600 for a military folder. So if a SG551 semi-auto costs around $3,000 in Switzerland by the time you pay the 10% import tariff, cost of shipping overseas, cost of conversion parts, conversion process itself, and finally dealer mark-up... well... what do you think that rifle would cost? Keep in mind no one would do such a thing unless they could make some good money. Gun companies are not charities you realize. I guess we could have government funded socialist gun programs?
The 551A1 is an economy model. In order to keep costs down and appeal to a larger market, SIG has done all kinds of cost saving measures. Some, like the furniture, can easily be fixed. Lousy quality control is more of a concern, but I can tell you that a sales rep from SIG was down at CDNN inspecting every single 551A1 after delivery, so maybe they are trying harder these days, at least with this limited edition Swiss-like model? Some of you out there say SIG should have made an American produced SG550/551 and sold it for $3k or whatever. It's true some of you would have bought it, but after the initial rush, then what? SIG would have had a gun priced to compete with the FN SCAR and H&K MR556, but without that air of newness and video game fandom. I know a good number of people willing to drop $1,500-$1,800 on a brand name 5.56 rifle and far, far fewer willing to do the same for a $2,500-$3,500 one.
A comparison was brought up on a forum: the Steyr/Sabre AUG A3 versus the MSAR STG-556. I think that's a good comparison, too. Quality is great but at some point you start receiving diminishing returns. Also, as a dealer I can tell you I have heard a lot of complaining about the prices associated with the SCAR and MR556. For all of SIG's QC issues, there are a lot of happy 556 owners out there. Generally speaking it seems to have become a reliable, reasonably accurate, user-friendly platform. It uses a good barrel, good receiver, and good bolt. These are important. Furniture can be replaced but receivers can't. The 551A1 is just another development of the 556 Classic meant to appeal to people like myself who want a clone of a SG551, but are not willing to shell out over $3,000 for it. Call me a cheap bastard but there you have it. It's a range toy for me and not a rifle I would ever use for defense unless by chance. Still, the core system of the rifle is proven, and critical parts breakages seem pretty low with this series. One of the weakest points of the 556 Classic, the stock, is gone on the 551A1 also. The sights are basic and for a serious shooter probably should be replaced, but for a plinker on a budget they will do for a while, at least. I really do hate manufacturers that ship guns with all kinds of rails and not even BUIS, but that is just me. Somehow it feels like an incomplete rifle. For those of you wanting a SG551 clone you just have to ask yourself, how much am I willing to spend and how close is close enough? For me, I guess the 551A1 is around the compromise point. It has a good barrel, takes Swiss mags, has a Swiss stock, and I can always replace parts later with original Swiss ones if I decide to.
UPDATE: Some parts on this 551A1 were swapped with Swiss style parts. To see what changes were made, plus test firing of this rifle, watch this video: