Monday 27th March 2017, Official Blog – Airsoft Gun Reviews, New Releases, Tech Tips and more!

WE MP9 Big Bird Airsoft GBB Gas Gun Review

Overall Score



Build Quality




We are reviewing the WE MP9 Big Bird, or as it is known in its real steel counterpart the Smith & Wesson M&P (Military and Police) 40. As this gun is based on a the real steel there are many carryovers from the real gun that make the this gun what it is, starting with the Polymer frame and going to the trigger safety.

First Impressions:

When you get this gun you are going to be thrown by the name of it: “Big Bird.” Even the box may throw you off as it has a picture of a Toucan on it. I guess it is fitting as the compact version is known as the Toucan. The name “Big Bird” comes from the shape of the back straps, which we will get into with more detail later. The gun has a good weight and a great feel. It is the epitome of the training weapon when you pick it up. The version I got for this review was the blue model. By having a bright color, it is perfect for uses in training simulations. The gun also comes in 3 other colors that include black, tan, and purple.


What’s Included:

When you open the box, you are somewhat overwhelmed as there are a lot of parts in the box as the gun comes with one magazine and six interchangeable back straps for your comfort. Three are black and 3 are pink, yes I said pink. Remember there has been an influx of girl shooters playing airsoft and they need a training weapon too. You will also get a manual as per WE standard packaging.


Gun Specifications:

Length 8 inches
Weight 2 lbs
Propellant Green Gas
FPS 337 w/ .20g BB’s
Mag Capacity 24 + 1
Rails One rail on the lower receiver
Inner Barrel 3 1/2 inches

The Breakdown

  • Externals 4

The externals of this gun were in no way disappointing, the polymer used for the lower receiver is high quality and highly durable. It has a feel that almost screams “Pick me up and shoot me.” One of the best features on this gun is the interchangeable back straps. Expect this to be the norm with Airsoft pistols from here on out. The majority of manufactures are doing this now. As I said before the gun comes with a total of 6 back straps, one of which will be installed on the gun. On the one we reviewed it was the black small size. Now the name of the gun is Big Bird and as I stated the name comes from the back straps. The shape of the back strap is very similar to the body of the bird that is on the box. Other than that there is no reason to call it a Big Bird.


Now changing the back straps may be difficult as the manual does not say anything about it. However by looking at the included back straps you can see a hole running through the center of the back strap, when I saw that I knew it had to be how it attaches. And it is at the base of the pistol grip; once you take the mag out you will see a half circle plastic base plate. Take this base plate and turn it 90 degrees counterclockwise then pull straight down. The back strap should pull right off. And to re-install another, one reverse the process.


The upper receiver is a full metal assembly, as you would expect from WE. The rear of the slide features serrations for ease of gripping the slide to rack the slide to chamber the first round. On the right side of the lower receiver you will find what has been said by other to be a unique serial number. Now I know that the serial number on this model is WET10670 and I know that the WET stands for WE Tactical. Maybe the numbers are the order in which the guns were made. But as per previous guns have come out the serial number is not unique; they are the same number throughout all of the guns. One other thing on the externals were the sights, they are a standard three dot system. A nice addition to them, and they are glow in the dark!


  • Power 3

This gun performed incredibly, the firs shot came out at 337 FPS! This for a WE gun is pretty high; now the lowest FPS we got with this gun was 261. That’s not too bad considering it was on the second mag when I got that FPS. I would have to say that this gun has a hard kick as you would expect to get from a WE. But the overall power of the gun is absolutely great.


*All testing done with AirSplat Green Gas

  • Build Quality 4

The gun is built to the highest standards, which I know that can be funny to say when you are thinking of an airsoft gun, but these are really made with care. The polymer used for the gun is a high grade making the durability top notch. The feel of the interchangeable grips are great, the largest back strap provided the most comfort for me. The slide has good weight to it on its own and it is not as heavy as some of the other WE guns out there. But I suspect that is why it has such a kick and good FPS as the weight is not an issue to move when being fired.


The gun has a minor rattle that you will find in any gas blow back pistol–nothing to be worried about. We did find that there was a pin that was over installed in the gun. If you look on the right side of the gun there is a black pin directly above the trigger. This pin goes through the gun and comes out on under the tear down lever. Now we were having issues doing the tear down and it turns out that the pin was pressed too far in making the tear down lever get stuck. But once we figured it out it was fine. We just tapped the pin back the other direction a bit and it worked out perfectly.

  • Internals 4

I was quite impressed with the internals on this gun. Yes you have the standard hop up assembly that WE is known for and the inner barrel is 3 ½ inches, pretty normal. But one thing I was impressed with was the spring guide rod; it actually locks into place similar to that of the KJW and KWA products. It was a happy change of pace on the internals. Everything else is pretty standard per WE; metal hammer system, and a plastic nozzle. The slide lock is ambidextrous and goes through the trigger assembly, so be careful if you intend to modify it.


  • Performance 4

I was really happy with the performance of this gun. I was able to get 2 full mags on this gun with one fill of green gas. And there was a little left at that time, maybe enough for 3 or 4 shots. In my book, that’s pretty good. The gun did not have any feed issues; we put about 1000 rounds down range to make sure that the gun did not have any hiccups. Everything about the gun performed as it should with the exception of the minor issue with the tear down lever being stuck. But I don’t imagine that will be a normal issue.




The gun is a solidly sound piece of equipment that performs to the expectations you would look for in a pistol. The overall feel of the lower receiver is perfect, it does not feel cheap like a spring pistol and it feels close enough to the real thing to be able to be used for training. The colors are a big upgrade, offering customers one of 4 very popular color options. And by including the back straps, you get a gun that will fit any shooter.



This gun has very few cons, I am actually hard pressed to think of one. I mean they sell additional mags, it has alternate back straps, hold enough gas for 2 mags, and has great FPS. Not to mention it is reliable. No cons to think of!


This is a gun that you need to get if you are a fan of the M&P 40! It will replace the non blowback you may have purchased in the past and become your next primary. It has everything you want and nothing you don’t. As the kids would say, “This gun is BEAST!” To translate, “This gun is awesome!” Go buy it and enjoy it.


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

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  • Whitman Lam

    Would a set of Real Steel M&P 40 day/night sights fit on this airsoft gun ?