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    Echo 1 SOB1 AEG


    Echo 1 SOB1 (Special Operations Branch) AEG review by Booligan
    Discuss this review HERE

    Table of Contents:
    Basic Gun Information
    First impressions/Packaging
    Gun Specifications

    It's been a little while since we've seen anything completely new from Echo 1, and the Special Operations Branch (SOB) kind of snuck onto the scene in the last few weeks. This extremely unique AEG has some interesting features including a retractable stock, flat top optic rail, full metal RIS front end, a specially designed magazine, and an aggressively styled front end. It's a very unique collection of parts applied to a sturdy metal body with quick disassembly design, and fitted with a stout V2 gearbox. I'll discuss all of the various aspects of this AEG in this review, so keep reading for more info!

    I was sent this SOB directly by Echo 1. It is available at most major airsoft retailers including Evike, where it is priced at $250.00. This includes Echo 1's warranty against factory defects which will cover you against any issues that may arise in your first month or so of owning the gun. There are two SOBs available, the 1 and 2. The SOB1 being reviewed today is the full size variant, while the SOB2 is the shortened model with a side folding stock that is designed for CQB use.

    Basic Gun Information:
    The SOB is an AEG modeled after a submachine gun, featuring a RIS front end, flat top optics rail, and a retractable crane stock. These are features that, when combined, make for a VERY customizable platform to tweak to your liking. It has a metal upper receiver combined with a polymer lower for a realistic look and feel. It has the same metal content as the real steel firearm that it's designed after, making it a full metal replica.

    First impressions/Packaging:
    Echo 1 has revamped their packaging with this gun, giving it a very stylish box emblazoned with an image of the American Flag. Inside the box, high density foam keeps everything safe during transportation, and it is a tight fit, making it pretty hard to remove the gun from the packaging. I was VERY impressed with the gun once I pulled it out of the package as it has a very nice, somewhat heavy feel to it that made it seem extremely realistic.

    Along with the gun itself, Echo 1 included two unique hi-cap magazines, KAC style rail covers, an 8.4v 1200 mAh nunchuck battery with trickle charger, and a cleaning/unjamming rod. It's a pretty basic package, but add some BBs and you're ready to roll! The battery is certainly serviceable, but for competitive use, I'd recommend going with an upgraded battery.

    From this point on, click on the thumbnails to view full size photos
    Box art

    Gun Specifications:
    Weight: About 5.5 lbs
    Length: 26-29.25"
    Width: 2.25"
    Height: 9.75"
    Sight Radius: N/A
    LOP: 12-15.25"

    As mentioned before, the SOB is a full metal replica, as the metal content is the same as the real gun would have. It has a matte black finish that makes it look quite realistic, however the finish will show some scuffs with time. The overall construction seems quite solid, with the exception of the stock adapter, that has some free play where it slides over the receiver. I eliminated this free play by placing some loop side velcro on the top and bottom of the receiver where the adapter slides over it, closing the gap and eliminating the free play entirely.

    External overview, right side
    Overview, right side

    The crane style stock is one of the big selling points of this gun, as it gives you a comfortable cheek weld with the ability to adjust it for various lengths of pull. It attaches to the gun via a 6 position metal stock tube. The battery is installed in the crane stock, however the buffer tube has enough room to fit a buffer tube LiPo, letting you swap out the stock for an aftermarket unit. I've since swapped it out with a Magpul CTR stock which fit quite well with a minimum of free play.

    Stock unit
    Stock fully extended
    6 position stock tube with wiring visible

    Moving forward, you'll hit the receiver which is split into two components, the upper and the lower. The lower receiver is made of polymer and houses the fire controls. The pistol grip is integrated into the lower receiver, and comes complete with an easily adjustable motor base. The selector switch is ambidextrous, making the gun very easy to use for both righties and lefties. At the front of the lower receiver, you'll find the paddle style magazine release, which works along with a button style mag release, giving you several options.

    Pistol grip
    Motor adjustment base
    Fire controls

    The upper receiver is made of metal and serves as the solid backbone for the gun. On the right side, you'll find the faux ejector port that is linked to the custom designed cocking handle. Pulling the handle back slides the metal faux bolt back, allowing access to the hop-up adjuster. The flat top optic rail mounts up to the upper receiver using the claw mount points.

    Upper receiver
    Ejector port
    Mock bolt pulled back
    Cocking handle
    Cocking handle locked back, yes, you can slap this thing

    At the front of the receiver, you'll find the full metal RIS with rails at the 3, 6, and 9 o'clock positions. The rail mounts extremely solidly to the receiver, due to the two point mounting system. There are several threaded holes allowing for the mounting of QD sling points. There is a little bit of room inside the RIS if you wanted to attempt to mount a small LiPo battery at the front, allowing you to install a retractable stock with some custom work and rewiring.


    The outer barrel is made of metal and is mounted very securely to the receiver. At the front of the barrel, in place of a front sight assembly, you'll find an aggressively styled block that meshes up with the top rail. The block itself has the 14mm- threaded muzzle attached, however the threaded portion is not removable. The included flashhider is a metal orange painted birdcage unit with a plastic ring glued on giving it a unique look. I removed it, and a different unit is installed for the review pictures.

    Outer barrel visible inside the RIS
    Front block

    A full length top rails is installed, giving you the freedom to mount your choice of optic or iron sights. There are no sights to speak of included with the gun, however rudimentary aiming can be done using the slot in the middle of the top rail.

    Top rail with Magpul MBUIS installed

    There is a single Echo 1 trademark located on the right side of the magwell. Along with that marking, you can find a "Made in China" stamp located on the motor adjustment plate.

    Echo 1 trademark

    One of the unique parts of this gun is the magazine. The magazine is a straight unit, instead of the curved unit normally found on this type of SMG, giving it a very unique look. The magazine is a hi-cap unit, holding about 200 rounds and featuring a bottom mounted winding wheel. Echo 1 was kind enough to included two of these magazines with the gun. The SOB retains full compatibility with standard MP5 type magazines, so spare mags are a piece of cake.

    Feeding bits
    Winding wheel

    Performance after a 500 round break-in period, using Matrix .20g BBs, shot through a Madbull Chronograph is as follows:
    High FPS: 411.9 FPS
    Low FPS: 406.6 FPS
    Average FPS: 408.2 FPS

    Rate of fire using the stock 8.4v battery is somewhat low, which is not surprising due to the high torque motor, gears, and hot spring. Using the stock battery, I was able to get 13 RPS, increased to 19 RPS with an 11.1v 1800 mAh LiPo battery. I want to get this set up more for CQB use, so I'll probably be swapping out the high torque units for high speed pieces, and downgrading the spring to make for more CQB friendly velocities and performance.

    Range and accuracy is of course improved using heavier ammunition, so I threw in my trusty Echo 1 .28g BBs and placed my torso sized targets out to 120', 140', and 160'. The hop-up is very effective at spinning this heavier weight ammunition, and surprisingly, I was able to get consistent hits on all three targets. 140' is this gun's sweet spot, as I had zero issues hitting the torso sized target at that range. At 160', your hit percentage drops a little bit, down to 75% or so, but I'd still feel comfortable engaging targets out to that range.

    Inside the kick ass externals, you'll find some very decent internal components. The SOB1 utilizes a quick takedown design, only requiring you to remove two pins in order to access the gearbox and hop-up. After taking out the pins on the stock adapter and at the front of the lower receiver, you can slide the lower receiver out of the gun, allowing you to get to the hop-up and inner barrel.

    Lower receiver with gearbox installed

    After taking out the screws in the grip and taking out the selector switch, you can pull the gearbox out of the receiver. Once removed, you can take it apart like any other V2 gearbox.

    Gearbox removed from receiver
    Other side of the gearbox

    The gearbox comes equipped with 7mm ball bearings, a ball bearing equipped metal spring guide, steel torque up gears, and a polycarb piston with ported head. It has a high strength spring, which allows this short barreled gun to shoot above 400 FPS. The gun has a standard ACM shim and lube job, so regreasing and reshimming it wouldn't be a terrible idea. Compression is pretty good, and after swapping out the o-ring for an x-ring, I got an additional 10 FPS.

    7mm ball bearings
    Internal components
    Ball bearing spring guide
    Polycarb piston

    The included motor is a high torque unit, which is long length. It has an Echo 1 sticker, and the magnets make it quite hard to rotate by hand. The rest of the wiring is fairly thin, which could cause some electrical resistance.


    The hop-up unit is plastic, and is sealed up with some sort of adhesive. Echo 1 had an orange Madbull bucking installed, as an out of the box upgrade. The inner barrel is brass and is 229 mm in length. The adjuster for the hop-up is underneath the faux bolt, which is accessed by pulling back the cocking lever.

    Hop-up unit

    The SOB is ready to be modified, due to the AR type stock, flat top optic rail, and full metal RIS. In my case, I threw some Magpul parts on it, including a CTR stock, MBUIS sights, ladder rail covers, and alternating between an RVG grip and a Madbull XM203. I swapped out the flashhider for a Bravo Surefire type unit, giving the front end a very aggressive look. The looks of this gun seem to polarize the airsoft community, with some people loving it and some hating it, but the customizability of the whole thing makes it easy to tweak to fit your liking!

    With RVG grip
    Ready to rock and roll with an XM203

    Full metal, sturdy construction
    Flat top optic rail and aggressive front end
    Full metal RIS
    6 position adjustable AR style stock
    Includes two of the unique straight magazines
    Great internal components
    Skirmishable performance out of the box

    Shoots a little hot for CQB use, but works well enough for field use
    Somewhat heavy, some users like a lighter gun for SMG use
    No included aiming devices
    Stock adapter wobble – easily fixed with some velcro

    I had heard rumors and whispers about this gun while it was in pre-production, but I was really surprised when it hit the scene a week or so ago. It combines some really interesting and unique parts to make for a pretty awesome looking gun. Echo 1 put together a great package with this thing, as it would cost well over $300 to build this yourself, if you could even track down all of the parts used. Overall, this thing is great as-is, and amazing with a few simple external mods, and I can't wait to turn some heads on the field with it!

    Many thanks again to Echo 1, and of course, Airsoft Retreat!