CAA M4 CQB Airsoft GBB Rifle - King Arms

"So this will be a bit of a long-winded review, but with good reason. I want to simultaneously give this gun 5 stars and 1 star, and you'll see why. Read on.

I purchased this gun early on in its production run, serial # 0000615. I was able to determine through research that all of these CAA licensed guns are OEM'd by King Arms, so the internals are KA/WA/G&P Magna compatible, which bodes well for upgrades and spare parts. I did my research, of the companies doing this system KA is the lowest quality but still generally good reviews, and there was a great promo going on (I got it for just over $200). So I took a gulp and ordered the gun. I'm relatively new to GBBRs so I figured this would be a great learning platform, and wouldn't be the end of the world if it broke after a few months of regular playing.

Gun shipped quickly, arrived nicely packaged in a very snazzy CAA box with black foam inserts. Came as pictured with extra grip options, rails, a low-pressure nozzle for CQB, buffer spacers, a speedloader, an allen key and a cheek riser for the stock. I also ordered a mock QD suppressor with it, and my first task was to examine the orange tip for removal. To my great surprise, it was NOT GLUED ON OR PINNED IN ANY WAY. Screwed straight off without even trying. Really cool, I thought hey, this is meant to be! This may be an issue with this first run of guns, but as handy as it was it did NOT say anything good about their QC.

First impression of the gun - it is STUNNING. The CAA furniture looks as good as if not better than any Magpul stuff to my eye, and the full metal EVERYTHING felt very solid. Pulling out the rear receiver pin and opening the hood revealed standard GBB internals - nice metal charging handle, metal bolt carrier, durable polymer bolt, really nice-looking all-metal... well, everything. I grabbed some thick silicon oil and soaked everything down, which I've read is a good call when first running the WA GBB system. All looked in order.

So I grabbed a can of EF green gas, charged and loaded the included mag and slapped it in. It fed about 5 rounds and then quit feeding, though it was still shooting. Assuming I'd done something wrong, I reset everything, made sure the mag was in straight, and kept shooting. It would feed a few rounds - almost half a mag on my second go - and then stop, no more BBs, just gas coming out. As I was shooting, the cycling started to feel nasty, bolt sticking, no good. Fearing the worst, I got out my good light and broke it open again. Here's what I found - again this is after less than 3 MAGS run through it and a trip to my local tech (Fox Airsoft, you guys RULE):

- The screw for the roller bearing on the hammer had come loose and was chewing up the side of the bolt carrier.
- The top seal on the mag had torn.
- The loading nozzle wasn't shaped right - molding error with the plastic.
- A tiny pin was sticking out of the bolt and was well on its way to eating the inside of the bolt carrier.

Needless to say I was upset. Jarrod at Fox told me to go home and RMA it straight away, the Fox guys can't get WA parts and they aren't hot on GBBRs so he said to fix it would be far more expensive than just shipping it back. I was crushed - such a beautiful, rock-solid-feeling weapon down the drain. I also realized quickly that Evike would (through no bad practices) be alarmed that the orange tip wasn't glued, and could have easily blamed it on me and refused the return with good reason to do so.

Feeling defiant, I decided to give it one last go and try to fix the problems. I figured that with some small jeweler's files I could re-shape the loading nozzle and file down the side of the pin on the bolt. Super glue for the torn seal on the mag and a tiny flathead to tighten all the screws on the gun. After about 2 hours of work, I put everything back together, lubed it again and prayed.

And lo and behold - it now runs flawlessly. I found a local guy who was selling some G&P Magpul PTS mags so I snagged those, and now this puppy shoots better than she looks. The recoil is similar to a 22lr rifle, maybe a hair more travel but less torque. Sounds fierce, bolt catch works great. Rate of fire is pretty fierce, definitely much, much higher than the 12rps the box claims - sound more like 18-20. A bit of a gas hog - I blew through nearly 2 cans of gas testing it. And CRAZY accurate - I was able to easy tag within a 12" circle at a good 50 yards. The hopup adjustment is great, you remove the handguard to reveal a very nice ring around the outer barrel that feels very solid and works very well. I'm inclined to think it comes with a 6.03 or .02 TBB installed as it's way more accurate than my buddy's stock Elite Force M4, and those have decent barrels in them (or so I hear).

So if you're willing to take the risk, or if you're a handy tech or just not afraid to try tinkering, this gun seems so far to be a great deal. Have not fielded it yet, will post an updated review if needed once I get some real trigger time. But I was blowing through mags all day with zero issues after fixing all the problems.

Pros -

Looks INSANE, all the perks of an M4 platform with a really unique appearance. Great for standing out from the crowd.

Overall fit and finish - other than those issues discussed above - is top notch. Almost zero stock wobble, no loose bits. Selector switch is quite firm, pins fit well, charging handle feels very solid.

Very high ROF, great for CQB work.

Comes stock with a very nice MBUS-style rear sight.

Extremely accurate with minimal hopup tweaking.

Includes a low-pressure nozzle so no NPAS needed, takes a bit of work to swap but still very practical.

Makes you feel like Special Forces from 2025.

Removable cheek riser and rail on stock is a very nice feature.

Grip is extremely cozy and has a variety of plates to size to your hand.

VLTOR upper receiver is a subtle but nice touch.

Sounds MEAN as HELL.

Cons -

CAME COMPLETELY BROKEN AND NEEDED A FAIR AMOUNT OF WORK TO GET RUNNING. (big con for many)

Definitely a gas guzzler - don't expect to run green/top gas in this thing unless you've got cash to burn.

Requires lots of lubing and maintenance.

Trades look kind of cheesy, but not too bad.

Stock magazine is definitely junk - the PTS mags I got run 1000x better, hold more gas and have MUCH nicer seals.

Comes extremely tricked-out but has an ugly, old-school hard mount front sight, which I will replace soon.

Recoil could be harder for my taste.

Stock bolt/nozzle assembly is all plastic, though it does seem pretty solid.

The cheek riser prevents the charging handle from cycling fully unless it's in the 3rd or 4th position out.

So sorry for the long read, but my experience was an eventful one. As of right now, I give it 4 1/2 stars in its current standing. However, when I was told by my tech that it was DOA, I would have given it -11,345 stars out of pure frustration at having a $300 gun be in that bad of shape out of the box.

In summary, if you're a handyman and want a sweet gun at a great price that you'll need to do some at-home QC on, then go for it. It worked great for me. If you're looking for Innokatsu reliability as soon as you cut the tape... save up another $300 and look elsewhere.