"This is a solidly built weapon system and possibly the most fun gun out of the 15+ airsoft guns I've owned. This is a long review but so far the only one I can see on Evike so please grab some popcorn and sit back and enjoy as I take you on a tour through this gun's lovely features.
When you first receive the box, you will get the SGR-12, 3 MLOK rails of differing lengths, a barrel cover, some bb's, and a 93 round half-translucent magazine. You can definitely feel the weight with this gun. When loaded it's just a hair over 4500 grams, or 10 pounds (I believe Evike needs to correct the weight on the description section). 90% of the weight is balanced above the grip with a slight rear bias which makes it not as painful as shouldering a front-heavy RPK or support weapon of a similar weight. Once shouldered it's actually quite comfortable to hold and not too bad. Thankfully it's about 4 inches shorter than its counterpart, the AA-12. It handles very nicely for CQB and doesn't really get in the way of anything as the barrel is just under 12 inches long.
Being a 10 pound gun, however, you're going to need a nice durable sling to carry it for an extended period of time. Thankfully, the sling mounts are made of a thick and durable metal, unlike the plastic sling mounts of the AA-12 which have a tendency to break off or get shot off. The iron sights are also made of metal but are not as useful because they sit very low on the rails.
The upper receiver and rails on the SGR-12 are made of a strong durable lightweight aluminum while the lower receiver and grip are polymer. The AA-12 is almost completely encased in polymer which makes it about half a pound lighter than the SGR-12, but feels a bit creaky and is not likely to survive being dropped or smacked on a hard surface. Not the case with the SGR-12. At the start of my third game, I unfortunately lost my balance while running forward and faceplanted into the ground. My gun went flying and the magazine flew out. I feared the worst but when I checked the gun, there were only 2 tiny scratches on either side of the gun with no sign of cracks or damage elsewhere. This thing is built like a tank.
Now, for one of the glaring issues: the magazine capacity is abysmal. You'll likely need the drum mag or 3D print an adapter (search on Shapeways) and convert an Angel Custom Firestorm/Thunderstorm drum magazine for use in the SGR-12. The Tokyo Marui drum is as noisy as the gun itself and can be a hit or miss from what I've heard (some say it feeds flawlessly and some say it needs a push from below to feed), while I've had positive experiences with the 3D printed adapter and Angel Customs drum. I've also used the 600 round high capacity magazines and while they fed flawlessly, they had a nasty habit of unwinding at random times when inserted into the magwell, plus they took something like 110 winds to feed half the mag. The magazines are massive, even bigger than a 308 magazine, and you'll likely need radio pouches to store the midcap or high cap mags.
Another issue: there is almost no space for a battery. You'll need the smallest 8.4v mini tamiya battery you can find, or use a 7.4v lipo stick or brick battery that's no bigger than 4 inches in length and no wider than 30mm. You cannot use a 9.6v or 11.1v battery with this gun; the built-in mosfet will blink red and shut off the gun. This is to prevent too high of a rate of fire which could compromise gear and piston timing. To use higher voltage batteries you'll need to replace the built-in mosfet. Speaking of which, the built-in mosfet works well and also has a nice voltage cut-off feature to save your battery when it gets low on juice.
Now, for the real reason you came to this page. The firepower. Oh goodness, the sweet sweet firepower... The rate of fire on this weapon is not great, but not terribly bad - it's actually good where it is. Fires about 600 times per minute. But you're firing 3 bb's per shot. You're putting down 1800 bb's per minute downrange. Your pants are no longer dry. Neither are the enemies'. On semi-auto it takes some time to spin up so your rate of fire is limited, but a new motor and mosfet can greatly improve that. The three hop up system really shines at mid range (75-100 feet) where the spread is just wide enough to suppress an area, but tight enough to ensure that at least one or two bb's will hit an enemy. The barrels and hop up are AEG spec so you can upgrade them for even more firepower. I believe the barrel length is about 10.5 inches (270mm). On the stock barrel and hop up I can reach out to 120 feet, maybe even more if tilting the gun upwards. It's absolutely devastating in a CQB setting, especially one that only allows semi-auto. It seems almost unfair and if it weren't for the fact that it's shooting only 260 FPS, it would probably have to be banned at every semi-auto only field. The only guns that can compete would be something like a fully kitted DSG or Polarstar build, but neither of those are even half as fun as using this gun. Oh and it's very loud when shooting which adds to the intimidation factor. Be prepared for some angry stares and callouts for overshooting your targets by "accident."
If for some reason you want to be sadistic and want to make more enemies than you already have on the field, Eagle6 sells upgrade springs for the SGR-12. If you're going any higher than their M90 I'd recommend getting the Retro Arms CNC bushings, an upgraded motor (I heard the ZCI 22 tpa short length high torque works well), and Retro Arms CNC piston. While you're at it, it would be a great idea to apply Loctite on every screw you can find on this gun. I've already lost one screw. The gun's action is so violent it literally shakes itself apart as it shoots. Taking apart the gun is a bit annoying, however, as there are a million screws to take out. However, the gearbox is a cleverly split design that even a novice could take apart and inspect.
Some things I would change are the dismal battery space, putting a sling mount further back, better motor, steel bushings stock (Nylon bushings in 2019, Tokyo Marui? Seriously?), wiring to deans, and maybe remove unnecessary parts to shed some weight. All these are quite minor issues and most of them can be remedied after purchase.
-Tremendous firepower (1800 RPM!)
-3 individually adjustable hop ups
-Decent range for a shotgun
-Durable aluminum upper receiver
-MLOK rail system, with RIS units included
-Metal sling mounts
-Mosfet w/battery protection
-AEG spec barrel, bucking, motor
-Upgrades such as spring, piston, and bushings available
-Shorter and easier to carry than the AA-12
-Nicely balanced towards the rear
-You notice yourself going to the gym more often, but instead of picking up chicks you are picking up your piss poor K/D ratio off the floor
-10 pounds is still 10 pounds
-Battery space :(
-Low mag capacity, drum mag is a must
-Somewhat slow trigger response, weak motor
-Nylon bushings (not a big issue unless you go over 310 FPS)
-Limited range overall (120 feet)
-Screws need to be Loctited
If this gun ever dips below retail price or Evike has a sale on it, grab it as fast as you can. You're missing out on one of the most fun and cleverly devised weapons to grace the airsoft industry.