Friday 24th March 2017, Official Blog – Airsoft Gun Reviews, New Releases, Tech Tips and more!

JG M4 SIR Airsoft AEG Gun Rifle 6613 Tan Review

Overall Score



Build Quality






This is a review on the JG M4 SIR in Tan. The M4 is the most popular of all assault rifles and is known for its ability to mount about anything you may want to it. The M4 has been described as the Barbie of the airsoft world, due to the fact that they make everything for it, from optics to M203 Grenade Launchers to vertical for grips and other massive amounts of furniture from a multitude manufactures.

First Impression:

The first thing you see is the plain brown box with a black and silver label marking it as the M4 S-System. After opening it you see the foam cut out for the rifle to be held in position perfectly, and keeps the gun safe during shipment. Once feeling the gun you can tell that the receivers are plastics and the furniture is a tan color, but not a Dark Earth that you commonly see now.


What’s Included:

The gun comes with a 8.4 volt small type battery as well as a standard wall charger. The gun comes with tan furniture on the hand guard, pistol grip and the LE style stock. You will receive a 300 round TM based magazine, a de-jamming rod, and a basic manual. The gun comes with Golden Ball 0.20g BB’s that is quite the improvement as most airsoft gun’s come with lower quality BB’s that you would normally want to avoid.


Gun Specifications:

Length Collapsed 30 1/2 in / Overall 33 3/4 in
Weight Loaded 8 1/2 lbs
Battery 8.4 volt 1100 mah Small type
Charger Standard wall type
FPS 438 w/ .20g BB’s
ROF 11.1 RPS on a 7.4v LiPo Battery
Mag Capacity 300 Rounds
Rails Quad Rail Hand guard, flat top rail system
Inner Barrel 363 mm


The Breakdown:

  • Externals 3.5

The body of the gun is a polymer and is painted grey over a black plastic. The LE style stock is adjustable to 6 positions with a sling point mounted on the stock. The pistol grip is a standard M4 style in the same color as the stock and the hand guard. The hand guard has top and bottom rails and comes with rail pieces to mount on either side of the hand guard. The gun also boasts a flat top rail to mount any optic you may want. The gun also has a folding front sight and a flip up rear sight. The outer barrel is a metal assembly, along with the buffer tube and all the rails.


  • Power 4

The gun has an incredible FPS coming in at 438 w/ .20g BB’s, which is incredible to get from a factory JG gun. Please keep in mind that most airsoft fields have a FPS limit of 350 to 400 depending on whether the field is outdoor or indoor. It has a ROF of 11.1 rounds per second as tested on a 7.4 volt LiPo battery back. The battery that comes with the gun is a 8.4 volt and will produce a lower ROF at 8.5 RPS. If you were to swap the spring out to a lower spring like a M100 or M110, that will lower the FPS and increase the ROF.


*All testing was done with a 7.4 LiPo battery

The battery installs in the front hand guard, as per most M4 variants. However the spacing will not allow for more than the standard 8.4 brick type battery or a 8.4 nun chuck battery. It will also fit the 7.4 LiPo battery as it is more compact.


  • Build Quality 4

The gun has a solid polymer body and is highly durable. Even though the gun is durable, it is not meant to take a high impact fall. The gun has a little creak to it and a light rattle coming from the 6 position LE stock that is to be expected from adjustable stocks. The assembly of the external components is done very well, and holds up to the wear and tear that you would expect it to go through in a milsim game. The selector switch has a fluid feel that snaps into place when going from safe to semi to full auto.


  • Internals 4.5

The internals of this gun are just what you would expect from a Mid level gun like this JG, but there were a few surprises. For example, yes the internal gearbox is full metal, but the hop up unit is a 2 piece plastic assembly. Not to say this is a bad thing but it is not what was expected. In addition to the hop up, another surprise was the fact that it came with a ported cylinder installed in the metal version 2 gearbox, it also has metal bushings. It is amazing to see the types of components that they are putting into the guns from the factory. They are getting closer and closer to being an upgraded gun. Now the motor is a JG high torque blue top motor, which helps to produce the impressive FPS of 438.



  • Performance 5

The gun performed perfectly. It did not have any feed issues with any of the magazines we used in it. We tried our standard combination of a Hi Cap 300 round magazine, which is the same as what the gun comes with as well as an 80 round PMAG and a 140 round SRC Mid cap magazine; they all performed flawlessly. The gun was accurate as you would expect to find from a factory JG M4, you are able to keep a grouping in a 4 inch cluster at 75 feet. But there is always room for improvement. The battery lasted a full day of game play, but it performed better with the LiPo battery that we did all of our initial testing with.





The gun is a top performer with a decent ROF, and in incredible out of the box FPS. The polymer body is solid and sturdy, making the gun light enough to use for a full day without it getting too heavy. The guns metal components such as the outer barrel and the buffer tube are made to the standard you would expect them to be. It has a full metal gear box and upon close examination you see that the cylinder is ported to enhance the performance of the gun. It has JG’s blue top motor that powers the gearbox to give the excellent performance it has.



As with any gun, there are some flaws. One of the flaws of this gun also happens to be one of the pros of it as well. It has an amazing FPS out of the box coming in at 438 FPS, which is just a bit too high for that average player. Most fields have a FPS rating between 350 and 400, so if you want to use this at fields, you may have to modify the gun to fit your needs. Another issue is that the gun has a 2 piece plastic hop up unit, making some upgrades easier, for example changing the hop up bucking or the barrel. The battery is front wired and it limits the size of battery that can fit in the hand guard. If you want to run something bigger you may need to run a PEQ box or a battery bag.



This gun has everything you want out of a starter gun, including a few things you would not expect. It definitely gives you the most bang for your buck. The gun has a tactical look as it is the S-System that has become one of the most popular configurations in the vast variety of M4’s on the market. The furniture being tan makes the gun ready for the majority of outdoor ops you may encounter at your airsoft field. By far one of the most well made M4’s you can get.


Which other airsoft guns would you like us to review? Let us know in the comments below!

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