Refurbishing a €20 AEG – Part 2

Having worked out what I have bought and fixed the loose stock, it’s time to try to work out why my €20 AEG won’t shoot. It didn’t come with batteries, but when I tried fitting the battery pack from my Umarex G36C, nothing happened when I pulled the trigger. The 7.4v Umarex battery is less powerful that the recommended 9.6v battery for this King Arms replica, but even so, it should operate. Clearly something is wrong.

I have to admit that I hate working with anything electrical. I have restored a fair number of elderly motorcycles over the years, and the bit I always dreaded was trying to sort out electrical gremlins. The crisply lined wiring diagrams never bore much resemblance to the rat’s nest of mismatched wires and soggy insulating tape that I found under the tank of most bikes. However, here I’m happy to report that the problem is fairly obvious, even to me.

The battery lives inside the vertically split front foregrip. To remove it, the sprung rear plate is held down and then one or both halves can be lifted off. Looking closely at the end of the Mini-Tamiya connector reveals that the wires have been fairly crudely bodged into the metal connectors. A couple of strands of one are even touching the other wire, clearly causing the connection to short-out.

It doesn’t take long to remake new, neater and more effective connections. I plug in the battery pack and it shoots in both semi and full auto modes. Hurrah! I haven’t yet tried it with BBs, but this AEG is certainly operational now.

Cosmetics

There is nothing else terribly wrong with this replica (and the red-dot sight works too – it just needed a new battery!) so all that’s left to do is to try to make it look a little better. I begin by stripping it down. To do this, you only need to remove a single pin, arrowed below.

This then allows the barrel assembly and upper receiver to be slid off to the front, being careful to guide the battery wires into the trough in which they sit.

The inner barrel and hop up can then be slid out to the rear and the inner plate that covers the ejection port can be removed.  

This disassembly probably isn’t essential, but it does give me a chance to check the internals. Nothing seems to be obviously broken or worn, the inner barrel looks straight and in good condition, the hop-up works as it should and I can’t see any other issues. It’s now time to start thinking about how to improve the way this rather tired AEGs looks. There is a fair amount of corrosion on metal parts including the ejector port cover, the handguard front plate and the collar that stabilizes the buffer tube.

All the metal parts are removed, sanded to remove rust and sprayed with a can of acrylic satin black that I have in the shed.

Then it gets cleaned thoroughly in warm water with a little washing-up liquid in it. This also gets rid of all the stickers. Finally, I go over all the plastics with a little silicon spray. When it’s dry, this helps to restore the faded plastic to its original black colour. Below you can see the two halves of the front handguard, on the left, after this treatment and on the right, before.

It may not be particularly obvious in this photo, but in real life, the difference is quite dramatic. All the plastics get the same treatment.

Then, it all gets reassembled. And I’m quite happy with how it turned out. It’s surprising just how much difference careful cleaning and touching up the rusty bits makes. This elderly M4A1 isn’t perfect by any means, but it is significantly better than it was.

The last stage is adding the carry-handle and rear sight. This replica didn’t come with either – it was fitted with a Swiss Arms red-dot reflex sight that I have decided to use on my Umarex G36. However, I was very happy to discover that it’s fairly easy to find replacements – I was able to source a generic Gexgune M16/M4 airsoft carry-handle and rear sight on Amazon for under €15.

It’s nicely made, fits well, incorporates elevation and windage adjustment for the rear sight and it matches the colour and finish of the rest of this replica. With this in place, it’s finally time to try some shooting.

Shooting

After all this work, I’m keen to find out how well this elderly AEG shoots. And the answer is: very nicely indeed! It has much more power than my Umarex G36C and it’s more accurate too. The Umarex AEG isn’t bad, but it does produce occasional flyers than hit the target at anything up to 2” from the main group. This one produces tighter groups at the ranges at which I shoot and the adjustable rear sight means that I can get the point of aim and point of impact to coincide.

The result of around 50, 0.2g BBs, from 10m in a mix of semi and full auto.

Problems? Well, very occasionally the trigger seems to jam in while in semi-auto mode, but flipping it to full-auto and back fixes this issue. The spring that retains the collar at the base of the handgrip seems much too powerful. Pulling it down to remove or replace the upper handguard halve takes a lot more effort that I’d have liked. And the Hi-Cap magazine rattles like a maraca when it’s full of BBs.

That’s about it really. I really don’t like peep-sights, but that’s just what you get with an M4 and I can always replace the iron sights with the red-dot sight I got when I bought this. The rate of fire in full-auto is fairly slow because I’m using the 7.4v battery from my Umarex AEG rather than the recommended 9.6v. However, I don’t find that a problem at all and, to me at least, this slower rate of fire sounds and feels more realistic than the rapid “Brrrr…” that some AEGs produce in full-auto.

Conclusion

I was nervous about buying an old AEG that wasn’t working, but relieved to find that refurbishing it was fairly simple and no more complicated than working on any other replica. I have enjoyed this project and I have even learned a little about how AEGs work, which can’t be bad. In addition to the initial price of €20, the only cash I spent here was on the new carry-handle/rear sight assembly, and even that was easy to find and relatively cheap. I could buy a more powerful battery and charger and replace the Hi-Cap magazine this came with for a Low or Mid-Cap, but do you know what? I don’t think I’ll bother. I’m quite happy with it as it is and I plan to just enjoy shooting it for the moment.

For not a great deal of effort I have ended up with a functioning AEG that’s fun to shoot and doesn’t look too bad as a replica of the iconic M4. This King Arms M4A1 has good weight (just over 2.9kg with batteries and the carry handle in place), looks convincing and shoots well. For a total outlay of just €35, I’m happy with the result of this project. If you are offered an old AEG that needs a little TLC and you’re willing to put in a little effort, perhaps it might be worth considering?

Happy shooting  

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Refurbishing a €20 AEG – Part 1

Umarex H&K G36C IDZ

Refurbishing a €20 AEG – Part 1

You don’t get a lot for €20, especially not in the world of replica guns. So, when I visited a boot sale recently and discovered a man with (literally) a plastic bucket filled with half a dozen or so well-used airsoft AEGs, I was immediately interested. All of them showed signs of hard use with rusty fasteners and cracked and broken plastic. But one caught my eye. It was a replica of the iconic M4A1 that had good weight, everything seemed to be there (including the magazine), the plastic parts were in good condition and it was fitted with a simple Swiss Arms reflex red-dot sight in place of the carry handle.

However, it lacked batteries, the buffer tube and stock were flopping around loose and appeared to be retained by a great deal of black insulating tape, the red-dot didn’t switch on and when I asked if the AEG was working, the answer was, “probably”. And a  smiling shrug.

I asked how much? He said €25. I offered €20 and he agreed. So, I unexpectedly found myself the owner of an AEG of completely unknown provenance. There was nothing on it to suggest who it was made by and no certainty that it worked at all. But hey, for €20 at least I’d have a red-dot sight that I could use on my Umarex G36C. Probably… Let’s see if I bought some cheap fun or an expensive source of spares for my other replicas.

The M4A1

Back in the early 1950s, the US Army began a truly futuristic project to develop a totally new infantry weapon. The SPIW (Special Purpose Individual Weapon) was planned as a fully automatic rifle that would fire not conventional rounds but steel flechettes at an astounding 2,300 RPM and from a weapon weighing only 3lbs. However, the project was dogged with problems and in 1964, the US Army instead adopted a modified version of the  ArmaLite AR-15 assault rifle as an interim solution until the SPIW was ready.

The futuristic Springfield Armory SPIW. It never got beyond the prototype stage.

The AR-15 became the M16 in US Army service, just in time for major American involvement in Vietnam, which didn’t work out terribly well at first. Early M16s, particularly when they were used in the heat and humidity of Vietnam, proved susceptible to corrosion and frequent jamming. Eventually, these problems were addressed and the M16 became the principal infantry weapon of the US Army when the SPIW project was finally dropped.

A US Army soldier in Vietnam with the then-new M16

The M16 finally proved to be reliable and effective, but it was always intended as a full size infantry rifle. However, Colt (who had purchased the rights to manufacture the AR-15) also later produced a carbine version, the CAR-15, which featured a telescoping stock and a 14.5 inch barrel compared to the 20 inch barrel on the M16. Initially, the CAR-15 was issued to crews of armoured vehicles and helicopters, where its reduced size made it easier to store and use.

A US Special Forces Delta operator with a CAR-15 during the First Gulf War in 1991

However, several US Special Forces units also began to use the CAR-15 and discovered that the slightly reduced muzzle velocity provided by the shorter barrel wasn’t a major issue. Soon other US military units became interested in this handy carbine version of the M16. Before long, it was adopted by the US military first as the M4 Carbine (with semi and 3-round burst modes) and later as the M4A1 with semi and full auto modes. Experience in Iraq and Afghanistan proved the worth of this weapon and now, variants of the M4 are used by most US Army and Marine Corps units.

US Marines training with M4A1s

First step – assessing the problems

Three functional problems were immediately apparent on examining this well-used M4A1 AEG. First, the buffer tube was loose, allowing the stock to flop around. In an effort to fix this, the previous owner had wound a great deal of black insulating tape round the base of the buffer tube, but this didn’t really address the problem. Second, when I got home and tried fitting a battery and pulling the trigger, nothing happened. Third, the red-dot sight didn’t work. This last issue is a real problem as this didn’t come with the M4 carry handle that incorporates the rear part of the iron sights, so I need to get the red-dot working.

In addition, there are a number of cosmetic problems. Almost all fasteners and metal parts such as the buffer tube collar, the ejection port cover and the front of the handgrip are lightly corroded. Most of the plastic is faded and grubby and there are stickers and the remains of stickers on the receiver. If it’s going to look half-way decent, all these things will have to be addressed. On the positive side, the receiver is in generally in good condition and none of the other plastic parts are cracked, broken or missing.

Finally, I have to work out what I have bought. I can’t see a manufacturer’s name anywhere on this replica. The receiver is heavy plastic with nicely engraved Colt markings and the battery fits inside the handguard which is split vertically. The magazine release and telescoping stock work as per the original and the charging handle retracts, though all it does is open the ejection port to give access to the hop-up adjustment. The forward-assist on the right side of the receiver moves, though the spring-loaded button doesn’t do anything.

The whole replica, with magazine but without batteries or BBs, weighs just over 2.6kg. After a great deal of looking at photographs of AEGs (the M4 and its variants must be one of the most common AEGs), I believe what I have here is a King Arms M4A1 Ultra Grade. King Arms are a Taiwan-based manufacturer of airsoft replicas and accessories and this particular replica seems to have reasonable reviews which makes me think it’s worth trying to refurbish.

Fixing the loose buffer tube

The first job is to fix that loose buffer tube and stock. After removing yards of black tape, nothing is obviously broken which is a good thing, but the base of the buffer tube and the adjustable collar aren’t sitting firmly against the rear of the receiver as they should.

All that insulating tape wasn’t actually doing much… You can see here the gap between the base of the buffer tube and the rear of the receiver and that the buffer tube can move from side to side. The screwable collar on the buffer tube should be flush with the plate on the rear of the receiver.

The plastic stock is removed by pulling the adjustor down all the way and sliding the stock off the end of the buffer tube. This then reveals an end-cap that is secured by a small hex screw. 

Looking down inside the buffer tube with the end cap removed reveals a cross-head screw. Unscrewing this allows you to remove the buffer tube.

With the buffer tube and retaining screw removed, the problem is clear.

Someone has replaced the retaining screw with one that has the correct thread but is much too long. You can see where they have tried to force the blank part of the screw into the threaded part of the receiver. When this hasn’t worked, they simply wrapped a length of insulating tape round the base of the buffer tube to hold everything in place. Happily, this bodging hasn’t damaged the thread in the receiver and simply swapping for a screw of an appropriate length fixes the problem completely.

Well, that was easy! If the rest of this refurb is as simple, I’ll be very happy indeed.

But, in the next part I’ll be doing something that I don’t enjoy at all when I take a look at the electrical side of things to try to find out why this AEG won’t shoot.

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