Some articles of information in this review were provided by "Anders", co-author of the Practical Survival blog http://thepracticalsurvivalist.blogspot.com/
The SGL 21-94 is one of the best AKs on the market today. Made in the same factory as the Russian military AKs, the SGLs are imported into the United States in an import-legal configuration (SAIGAs). When they arrive in Las Vegas, Nevada, FIME Group, LLC., puts them back into their sporting configuration: pistol grip, (in this case) folding stock, standard handguards, muzzle brake, et cetera. The 7.62x39mm SGL series is the best deal when it comes to AKs on the civilian market. The fit and finish are absolutely superb (though the finish is easy to scratch as it is paint-over-parkerization). Every part moves very smoothly as you would expect from a genuine, Russian AK. The SGL 21-94 is a semi-automatic clone of the AK-103 (sans pistol grip reinforecment plate) that Russia makes for export. The AK-103 is used by some Russian police and special forces units, as well as the Venezuelan military. As mentioned, the rifle is chambered for 7.62x39mm and accepts any standard AK magazine.
The SGL 21-94 has some unique features. The first of which is, of course, the side-folding stock, differentiating it from the standard SGL 21 models. The stock features springs only in the release buttons (one on the receiver, the other in the buttstock). Since there is no spring tension on the stock itself, it swivels freely until locked in either the extended or folded position. I prefer this as I have less springs to worry about replacing. The stock locks solidly into place in both positions, and has no wobble to it whatsoever. Below you'll see a photograph of the locking mechanism in the rear trunnion itself. As you can see, it's pretty solid.
Photographed is the spring-loaded button on the receiver. It allows you to fold the stock to the left-hand side of the rifle. This button is a little difficult to push at first, rifle depending, as the spring is sometimes stiff. However, with use, it'll loosen up. It will not loosen up to the extent that it is "floating" there, however, so any time the stock folds, it will definitely be from purposeful pressing of the button.
You may have also noticed that the buttstock shown above had a rectangular cut-out in it. It does look a little funny, but it serves a good purpose. This cut-out exists so the stock may fold over the optics rail attached to the left-hand side of the rifle's receiver. This rail was added as standard to all AK-74M and AK-100-series rifles in the 1990s. The SGL 21, being a '103 clone, likewise included this handy dovetail mount on the side of the rifle. Since it sticks out a bit, the stock had to be relieved on the left side for it to fold without interference.
The stock also features a button in the buttplate. This disengages the stock from the little lever on the front-left of the receiver. This lever holds the stock solid when folded, but is also easy to disengage when needed. The button does tend to push in the cleaning kit tab, but not enough that anything would fall out. When shouldered, this button pushes in a little bit, flush with the buttplate, slightly opening the trap door, but that is actually a very good thing: getting a peg into your shoulder each shot would suck.
The way the stock itself "works" when folded, and how the buttplate's button works, is explained in this next photograph. On the metal triangle-folding AKs, the stock was skeletonized. When it latched onto the side of the rifle, you simply pushed back on the lever shown below with your thumb to unfold the stock. It's not too difficult, but it is a stiff spring, so your fingers got to hurting after a lot of repeated use. Anyway, with the '100-series stock, it's obvious this would present a problem: it's not skeletonized. Therefore, when this button is depressed on the stock, it also pushes this latch rearward on the rifle itself. Once fully rearward, it disengages from the stock, allow it to once again be unfolded.
Since the stock folds, attaching a sling to the standard position would not work very well: your sling would be changing lengths every time you switched from folded to extended. That's no fun. The Russians decided that the sling should therefore be positioned on the front-right portion of the buttstock at the wrist. Though not perfect, this reduces the difference in sling length when folded and extended. Unfortunately, there is probably no other place to attach a swivel, so this set-up is most likely the best you will get. I have had no issues with it other than the sling occasionally twisting (the rear swivel can rotate 360*). I use a canvas sling, so this is not too big of a problem. If the sling folds, it will more or less conform to the body rather than poke into it like a twisted leather sling might.
Even though this is a 7.62x39mm AK, it features an AK-74-style barrel and barrel-mounted hardware. The SGL features an AK-74-style muzzle brake that uses standard rotation (left, loose; right, tight) that fits on a '74-profile front sight block. This helps with felt recoil and elimination of muzzle rise very well. The rifle will also accept AK-74and AK-100-series bayonets (not photographed) due to this. These rifles are also very accurate: about any SGL-21-series you handle will get around 2.0MOA (sans muzzle device). That is, two-inch groups at 100 yards. Arsenal sent a sight-in sheet with this rifle and, at 25m, all three rounds touched. Later on, after mounting a red dot, hits were constant at ~220m (~240yds.) off-hand with this rifle using Wolf ammunition on a torso-sized target. The muzzle brake was helpful in keeping muzzle rise down, so returning the rifle to the target did not take long. Seen below is the AK-74-style front sight that is threaded for these muzzle brakes. You'll want to make sure you keep these cleaned well after each shooting session.
Overall, the Arsenal SGL is the best AK I have ever handled, period. There is no matching the quality of these firearms. The folding stock models can be had in either an AK-100 series stock (in this review) or a standard, metal triangle stock (designed for use on the AKS-74 rifles, but work well on the "'47s"). It is down to personal preference. The owner of this firearm went with the 100-series stock as it offered a better cheek weld and would be more comfortable when shooting in cold weather. If you want a no-frills AK, however, do not be upset. FIMEalso offers regular fixed-stock models for around $800. The accuracy on these is the same, as is the fit and finish. If you're wanting an AK in 7.62, definitely go with an SGL 21.