Gun Review: German Sport Guns (“GSG”) 522 SD

Unless you live under a rock like that guy in the GEICO commercials, you will have noticed the recent trend by gun manufacturers to offer replicas of military long guns chambered in .22 LR. These guns have flown off the shelves for two reasons. First, the economic double whammy of skyrocketing ammo prices and a never-ending recession has left many shooters feeling the need to lower costs by switching to .22LR. Second, it gives shooters the opportunity to train on a weapon that looks and feels like its big-brother AR, AK, Sig, or H&K. OK, there’s a third reason – they also look pretty darn cool! One of the more interesting designs on the market is the 522 by German Sport Guns (“GSG”).  The 522 is a close rendition of the venerable Heckler & Koch MP5. In this article, we test the “SD” version of GSG 522 and let you know if it’s really worth your hard-earned $400.

The upstart firm of GSG is based out of Höingen, Ense, Germany, a tiny village in North Rhine, Westphalia, in the Ruhr valley.  American Tactical Imports (“ATI”) is the importer. Formed in 2002, GSG first hit the market with their MP5 clone in 2008.  Based on the internet chatter I’ve read, the gun was anxiously anticipated but suffered from some initial growing pains.

Nonetheless, sales were brisk, and it’s a testament to the success of this rifle that HK bothered to sue GSG for trademark infringement. Now HK is marketing its own (Walther-made) MP5 clone. It makes you wish you could have been a fly on the wall at an HK executive meeting:  “Gentlemen, why the hell didn’t we think of this first?!”

GSG is producing a number of versions of this .22, including a clone of a standard Heckler & Koch MP5 A2 rifle, an MP5 “SD” rifle, a “light” version featuring a polymer receiver, and two pistol configurations, including a copy of the MP5K. This particular rifle is a full-size copy of the MP5 SD. The “SD” is a reference to the integral suppressor in the original HK, which is called a Schalldämpfer (sound “dampener” or “suppressor”) in German.

Not surprisingly, the “can” on the GSG 522 is a purely cosmetic faux suppressor: a mere barrel shroud. Apparently, some of the earlier versions were not “faux enough” to meet the strict standards of our friends at the BATF, and so a recall has been instituted.  If you own a GSG 5, you can go to ATI’s website to check out whether your gun is on the recall list.

The purpose of the fake can is primarily cosmetic, but it also offers some protection for the long, pencil-thin (.42 in diameter) barrel.  As most readers are aware, federal law requires any firearm that is equipped with a shoulder stock to also have a 16&1/4 inch long barrel.

The GSG-522 uses a straight-blowback design, rather than the more complex roller-locked operation of the HK MP5. The receiver is a two-piece clamshell design made out of die-cast zinc, held together by screws. The manual states that the end-user should not disassemble the clamshell, but I did it anyway. It’s one of those operations that requires three or four hands to get it back together, but I managed after about a half hour or so of trying. One tip is to use some heavy grease to keep some of the small parts in place while you line everything up.

The breech housing (aka “bolt carrier group” if you prefer AR terminology) is die-cast zinc like the receiver and houses a metal injection-molded steel bolt assembly.  The barrel is a 16¼ inch, 6-groove design manufactured in-house by GSG.

Overall, the .22 clone carbine echoes the same excellent ergonomics of the original MP5. It feels like it weighs slightly less than a real MP-5, but not enough so to make it feel like a toy. Having said that, the light-weight stock is the one part of the gun that feels more like an air-soft product than a real gun. It’s good enough to serve its civilian purpose (i.e. plinking, small varmint hunting), but it’s not rugged enough to stand up to any rigorous police or military training.

The two-stage trigger is a definite selling point. For a gun of this type, it is surprisingly good. I wouldn’t say that it breaks as precisely as a finely-tuned bolt-action rifle. In fact, it has a long pull and is a tad mushy – somewhat like a real MP5. Nonetheless, the GSG 522’s break is smooth, predictable, repeatable, and light enough so as to not cause flyers.

The 22-round polymer magazines for the GSG-522 are another high point. They duplicate the size and width of a real MP5 magazine, so they will fit in all your Blackhawk MP5 tactical gear. Although the mags are a single-stack rimfire design, they are thicker than necessary in order to approximate the size and feel of a real MP5 mag. The GSG mags also come with finger holds on either side and are therefore much easier to load than typical 22 high-cap mags.

Unlike real HK mags, however, the GSG units are a two-piece design made of plastic. When they’re fully loaded, there is a visible gap between the two halves. This gap is not, frankly, very confidence inspiring, and my initial impression was that these mags would last for a month and be finished. But after 2000 rounds they haven’t let me down yet.

One low point is the newly “redesigned” GSG sights, which are a deviation from the original HK design. The circle-in-circle design of the original HK MP-5 / G-3 rifles is one of the most intuitive, easy-to-master sight designs in existence. In the photo above, you can see a comparison between a real HK MP5K front sight (in this case, with the tritium insert on the left) and a GSG front sight post (on the right).  Both the HK design and the tried-and-true M-1 Garand type sights allow the shooter to frame the target in both the vertical and horizontal perspective, which is the key to their success.

The problem with the straight vertical posts on the GSG 522 is that it gives the shooter nothing to bracket the vertical perspective on, and therefore the shooter will tend to string the shots out vertically.  The conversion kit (discussed below) partially solves this problem by providing the user with an exact copy of the factory HK front site. Unfortunately, that only solves half the problem, as the kit doesn’t contain a rear sight drum.

Nonetheless, with a little practice I was able to get the round front sight/rectangular rear sight combo working pretty well. Of course, adding the red dot optic really solved the problem, as it makes the rear sight pretty much irrelevant. Another possible fix is to replace the GSG rear sight with a real HK MP5 rear sight assembly. I haven’t tried it myself, but I understand that it will fit, albeit with some slight modification to one of the screws.

Far and away the biggest disappointment regarding the GSG 522 is the sorry excuse for a Picatinny/Weaver rail that comes with the gun. It has two fatal design flaws. First, it’s made of flimsy hollow plastic and is therefore too flexible to support any real weight.  Second, it’s held to the receiver via two tiny screws. Given this crappy design, you can never really get the rail to tighten very securely to the receiver. As a result, there is a lot of lateral movement in the rail. Basically, it’s a totally useless POS and should be tossed back in the box and replaced with a “real” rail ASAP.

Fortunately, ATI will sell you a “real” aluminum “claw” rail for $15.00. They also make a very nice clone of the excellent Brugger & Thomet low mount (the photo above shows the GSG mount and a Bushnell TRS 25 red dot). Prices on the GSG “Low Tactical Mount,” as GSG has named it, vary from $20.00 to $65.00, so it pays to shop around.  The best price I could find was $19.95 from  It’s a very solid unit and, as discussed below, immediately solved the wandering zero issue I was experiencing.


Although the manual of arms is more or less the same as a real MP5, there are three critical differences. As many of you will know, the HK MP5 differs from most sub-machineguns insomuch as it fires from the closed bolt. The GSG 522 also fires from the closed bolt. The HK MP5 does not have a bolt hold-open feature. The GSG 522, on the other hand, does – the bolt will lock to the rear (i.e. stay in the “open” position) after the last round in the magazine is fired. The bolt stays locked to the rear even after the magazine is removed.  Once a new loaded magazine is inserted, the charging handle can be “slapped” forward in the same manner as a real MP5.  Or, the bolt can be closed on an empty chamber by pulling the charging handle to the rear for a fraction of an inch and then releasing it (similar to a Ruger 10/22).

The third difference is that the GSG has a magazine safety. The gun will not fire unless a magazine is inserted in a rifle.   This type of safety feature is good on a gun that will be shot mainly by civilian plinkers, but is not the type of feature that you’d want on a combat-oriented weapon like an MP5.

The GSG’s magazine release system is patterned after the MP5, in which the magazine release is made up of both the cross-bolt button and a paddle-type lever located at the rear of the magazine well. The 522’s magazine release paddle is textured but otherwise the same as an MP5. The safety is ambidextrous and is similar in operation to a real MP5, although the shape and texture of the safety differ somewhat from the original.

Disassembly / Reassembly

Those of who are familiar with the simplicity and ease of disassembly of the original MP-5 design will be somewhat disappointed by the GSG-522 for three reasons. First, it requires a screwdriver and Allen wrenches to disassemble. Second, there are small parts to contend with. Specifically, the bolt carrier assembly is held into the receiver via a small metal block, which is held in place via a small Allen screw and washer. Third, the two retaining pins also differ from the original HK style pins insomuch as they are a two-piece unit which tightens with a flat-head screw. I replaced the two-piece GSG pins with factory HK push-pins, which fit perfectly.  Two sources for these pins are listed below:

Fortunately, GSG provides the end-user with a small screwdriver with interchangeable tips (pictured above). While the gun is not particularly difficult to disassemble and reassemble once you get the hang of it, I did actually have to take the unmanly step of resorting to the manual to figure out how to take it apart and put it back together.

And, honestly, the manual sucks. I’m not sure why, but it seems like manual writing is one of those jobs that always ends up getting assigned to the dumbest and/or laziest person in the company. Aside from not being very helpful, the GSG 522 manual had little gems like this:

Overall, I found the GSG to be a bit of a chore to clean. There are lots of little nooks and crannies inside the receiver, and because of the straight blowback design, lots of crud ends up in the “bolt carrier group” (to borrow AR-15 terminology) and receiver. It takes me a little less than an hour to do a basic functional cleaning job, perhaps as much as two hours if I really want to get in there with pipe cleaners and Q-tips to make it look really clean. The 522 needs to be cleaned after every brick (or so) of ammunition, especially if you are using the cheap stuff. After my last range trip, I was really surprised by the extremely heavy lead built up in the first 5 to 6 inches of the barrel.  Having said that, I was shooting a lot of cheap stuff on that trip, so maybe I should not have been that surprised.

According to Mike Cummings, one of the gunsmiths at ATI, the breech housing and bolt will require a thorough cleaning after approximately 5000 rounds.  This requires you to take the breech housing apart (which the manual discourages) or use solvents and compressed air.  If you decide to take the breech housing apart, you’ll want to make sure you note the orientation of the two long springs. They are slightly tapered at one end, and if you install them backwards, you will cause the gun to jam. Mike says he sees quite a few guns being sent in for factory service because of this. Again, this is the type of problem that a good owner’s manual could prevent.

Aftermarket Parts / Accessories

There are quite a few aftermarket stocks available for the GSG 522, including clones of the HK “A3” style telescoping stocks, and Brugger & Thomet Style side folder. Real HK stocks will not fit, however.

I decided to test GSG’s “Advanced Folding Stock.” It’s adjustable both for length (4 positions) and cheek weld (3 positions). It folds to the right and stays in place using a tension spring and has a removable ambidextrous sling attachment point. Again, prices on these vary from $70 to $100 so shop around. The “HK Specialist Store” in Greer, South Carolina seemed to have the most competitive prices in GSG accessories. Their customer service was excellent and they even shipped the same day as my order.

Overall, I think the stock is a worthwhile investment despite being a bit pricey. Again, the unit is not as rugged as you’d find on a real military rifle but it’s adequate for plinking. The only disappointment is that it doesn’t actually lock in the folded position with the SD model (the front SD handguard is too wide).

Being a confirmed HK guy for over 20 years, I strongly dislike the GSG-522’s factory-redesigned front sight post, so I spent $50 and ordered the GSG-5 / GSG 522 conversion kit from the HK Specialist Store. The kit contains a new trigger housing, left and right hand safety levers, a paddle magazine release, a receiver cap, a sling loop, two metal front site blades, eight polymer front sight blades, a sling loop screw, a cocking tube housing, a cocking tube handle, an SD style cocking tube handle and a few other miscellaneous parts.  The HK Specialist Store has the factory HK push pins in stock as well, so I had them ship a couple of them as well.

The photo above shows the GSG-522 with most of the retro-fit parts added to the rifle. The photo also shows the GSG adjustable folding stock. The whole job of converting the gun took about two-hours while I was watching a football game. Replacing the receiver cap was the toughest task, as it required the disassembly of the clamshell receiver.

The conversion probably would have taken half as much time if it had come with good instructions. The only set of instructions that came with the kit was a second copy of the owner’s manual. Unfortunately, the owner’s manual does not really do a good job of explaining the steps needed to do the conversion. While I was able to figure it out on my own, not having detailed instructions is inexcusable. GSG needs to get off its German ass and write some better manuals. Mach schnell!

One final modification that GSG owners may want to consider: a common complaint you hear about the GSG 5s and GSG 522s is that the screws that hold the rifle together are of poor quality and sometimes work themselves loose after extended firing sessions. In fact, the gunsmiths at ATI confirmed that this is sometimes the case. So far I have not had any issues. Nonetheless, one aftermarket solution to this problem is to replace the factory nuts and screws with higher quality aftermarket versions. Check out the “rrages” website if you are interested:

Field Tests: Accuracy & Reliability

Range time: this is where the GSG 522 really started to shine. As an initial matter, this gun is very accurate for its genre. In fact, the skinny little GSG barrel will run toe to toe with my highly-modified Ruger 10/22, which features a $300.00 Volquartsen bull barrel and a trigger job from Clark’s. When fed with high-quality match grade .22 ammo such as Remington (Eley) Target Rifle, the GSG consistently delivered ¼ to 3/8 inch groups at 50 yards. Federal Gold Medal Match HV also turned in respectable groups in the ½ inch range. Cheap mass-produced plinking ammo typically resulted in 1-inch groups at 50 yards. Still not bad at all.

The photo above was taken using a Leopold VX-II 3×9, set on 9 power, and Remington Target Rifle ammo (which is actually made by the British firm Eley). These groups show flyers which I attribute to a wandering zero due to the crappy plastic rail that comes with the factory GSG. It was these annoying flyers that prompted me to seek out a better solution for the rail.

After I replaced the POS factory-issue rail with the optional GSG “Low Tactical Mount” and cleaned the massively fouled barrel from the 600 round session, I was quickly able to turn in ¼ inch groups at 50 yards with the Eley-made target ammo. The group shown above is representative of the type of accuracy I think you can expect from this rifle once you replace the rail with something more substantial. Belding ground squirrels beware! Obviously, these types of results aren’t as easy to achieve with non-magnifying red-dot type optics or iron sights.

One note on the GSG Low Tactical Mount: it’s designed so that you can co-witness red dot sights with your iron (or, in this case, plastic) sights. If you want to use a conventional hunting scope with the Low Tactical Mount, you will have to temporarily remove the rear sight drum.  For my purposes, that was OK, but if you want to put the bigger hunting optic on the gun permanently, you may want to opt for GSG’s “High Tactical Mount.”

The photo above shows the types of groups I was typically achieving with cheap-mass produced ammo such as Remington Thunderbolt (40 gr. /  1255 f/s) and the factory rail. Again, some of the groups widened due to the POI shift from the crappy rail.

I achieved similarly sized groups with CCI Mini Mags (40 gr. / 1235 f/s), Federal “American Eagle” (38 gr. / 1260 f/s) and Winchester Xpert HV (36 gr. / 1280 f/s).  Incidentally, the gunsmiths at ATI recommended using CCI Mini-Mags, and specifically advised against Remington brand ammo. I personally think CCI Mini Mags are overpriced for what you get as they really provided no accuracy advantage. The CCI’s do seem to run a bit cleaner than many of the lesser-priced brands, however.

I also did some rapid-fire drills with the GSG 522 at 20 yards. The weight of the weapon creates a steady platform with no recoil, and I was able to turn out the following five-shots-in-two-seconds groups with the Bushnell TRS 25 red-dot optic:

The other most obvious high point for this gun was its reliability. By the time I finished testing, I had put approximately 2000 rounds downrange, and had only experienced 4 or 5 jams.  Most of those occurred in the first 60 or so rounds, and can be attributed to break in, and perhaps a bit of “operator headspace and timing.” Of the last 1200 round we fired, I had no failures and Chris Dumm only experienced one – which may have been ammo related (bad primer?).  For a semi-automatic rimfire rifle, I was pleasantly surprised by the reliability of this gun.

Having said that, you do have to feed this gun higher velocity .22 rounds. The owner’s manual recommends using ammo that generates at least 1200 ft/sec. The sample gun I tested seemed to work fine with somewhat slower fodder. For example, Remington (Eley) Target Rifle ammo was totally reliable, even though it only generates a muzzle velocity of 1085 f/s.  However, the test sample gun would not cycle my favorite match ammo, Wolf Match Extra, which only generates 1033 ft/s, so consider yourself warned.


To be honest, I started this project not expecting to be very impressed. In saying that, I don’t mean to suggest that I had any biases against the manufacturer or importer. It’s just that I had no prior experience with GSG products and my only direct experience with ATI products was with their excellent Korean-made 30-round MP5 mags and their inexpensive but functional 32-round extended magazines for the Glock 17. My comrade-in-arms and law, Chris Dumm, recently had a bad experience with an ATI AR-15 clone (the VK-22) in .22LR, but I was determined to not let that debacle influence my review of the GSG.

Rather, my bias stemmed from years of experience with military look-alike .22 autos and hi-cap mags. I’ve owned almost a dozen high capacity mags for my Ruger 10/22, from makers such as Ram-line, Butler Creek (including the Steel Lips) Eaton, Mitchell 50-round tear drops, etc., but none ever ran well for any length of time. The tried-and-true 10-round rotary magazine was the only 10/22 magazine that hasn’t let me down. A friend of mine owned an AK-22 back in the 1980s and although it looked pretty cool, it was not the most reliable gun. In addition, I’ve seen more than one guy at the local range have problems with their .22LR Colt AR-15 clones.  Thus, all of my prior experience told me that I should prepare to be unimpressed with the reliability of a high-cap .22. As detailed above, however, my instinct was completely wrong.

Maybe I should have been more optimistic. As Vince the “Sham-Wow” guy can attest, “the Germans always make good stuff.” As it turns out, the GSG will run toe-to-toe with my Volquartsen-barreled Ruger 10/22 in terms of accuracy, and is a hell of a lot of fun to shoot.  Just upgrade the craptastic factory rail (shown in pic below) and you will be good-to-go.


Caliber: .22LR (optimized for use with high-velocity .22 LR ammo)
Action: Semi auto, blowback operated
Capacity: 10 and 22 stick magazines; 110 round drum magazines
Overall Length: 33 & 3/4 inches
Barrel: 16.25″ ST35 steel
Rifling: six-groove 1:16″ RH twist
Trigger Pull: non-adjustable, single-stage; 5 lbs.,12 ozs (according to the factory).
Weight: 6lbs, 9 ounces, unloaded.
Sights: front sight is a vertical blade set in a dovetail, with vertical protective ears, rear sight is a rotary drum (similar to the original H&K design, but not as good).
Finish: Receiver appears to be powder coated, remainder is black plastic.
Price: MSRP: $399 (Retail Street Price).
Accessories: multi-tool, breech cleaning tool, 10 extra front sight posts, clamber flag, lock, crappy owner’s manual.

RATINGS (out of five stars)

Style  * * * *
It’s hard to beat the looks of an MP5. I’m going to take a point away simply because ATI added weird looking dots on the pistol grip and equally unnecessary horizontal lines on the trigger group. My understanding was that these cosmetic changes were made in order to get to get Heckler & Koch to drop its lawsuit against GSG. If the non-authentic look really bugs you, you can shell out $50 for the retrofit kit.  The fake suppressor looks cool, but be prepared for guys to approach you at the range asking about your can: they get a disappointed look on their face when you tell them it’s just a barrel shroud.

Ergonomics  * * * * *
Feels like a slightly lighter version of a real-deal MP5. The safety, charging handle, and mag release are in the right positions. The weight and balance are comfortable. What’s not to love?

Reliability  * * * * 1/2
The GSG 522 experienced a few hiccups running through the first few mags, but then ran smooth as silk. On the last two range days of the testing, we put roughly 1200 rounds downrange with only one cleaning and only experienced one malfunction (and even that may have been ammo related).

Customize This  * * * *
While this ain’t no Ruger 10-22, there’s a fair amount of factory “tacticool” that you can buy for the GSG 522 including dual mag clamps, flashlight holders, folding stocks, high and low scope mounts, laser mounts, etc. From the internet lore I’ve read, it seems that some of the stuff made by various air soft manufacturers will fit as well, but I can’t vouch for that.

Accuracy  * * * *
The GSG is not quite as accurate as a bolt-action Anschutz or a CZ 452, but it’s going to embarrass your stock Ruger 10/22.


Overall  * * * * 1/2
The GSG 522 is a lot of fun if you are looking for a low-cost range plinker with the added benefit of sexy looks and historic provenance.