The DBoys 500-round Extended Magazine fits onto most M4 and M16 airsoft AEGs. It’s an upgrade from the average 300-round magazines that come with the average M4/M16 AEG, giving you a 66% (or 200 BB) increase in BB capacity.
The DBoys Extended Magazine works just like any other AEG magazine. You load the BBs into a little plastic sliding door on the top of the magazine, filling up a large chamber. You then slide the little door shut and insert the magazine into your gun. From there you wind a wheel on the bottom of magazine (you can see the wheel in the picture above, at the bottom of the magazine, in the bottom right corner) until it gets hard to turn and starts to make a distinct clicking noise.
Having 500 rounds is great because you can just keep shooting without having to reload. However, about half way through the magazine, BBs will stop feeding and your gun will start to dry-fire. When this happens you need to wind the wheel on the bottom back up again. It’s not a huge deal, but it can be a chore if you’re in a actual airsoft skirmish and you have to stop to wind your magazine back up, especially when the whole point of a extended mag is to not have to stop to reload.
The DBoys Extended Magazine also claims to work with M4s and M16s from JG, AGM, DBoys, Classic Army and Echo 1, but that’s not entirely true. With my personal JG M4 2010 Upgraded Version I have to wiggle the magazine back and forth to get it to slide into my receiver and then forcefully slam the bottom of the magazine with the palm of my hand to get it to click into place (kind of like what your avatar does on Call of Duty: Black Ops when you close the top of the M60 after reloading it). The problem is that the magazine doesn’t go with the slight turn that M4 receivers have, making the back of the magazine scrape up against the M4’s receiver. Although slamming the bottom of the magazine does make it click into place and allows it to work normally, it makes reloading much slower and also causes some cosmetic damage to the magazine as well as inside receiver.
The magazine is very durable, however. It’s made completely of metal, excluding the wheel on the bottom, the plastic door on the top and a couple other little pieces. Even after upwards of 20 times of slamming it into my M4 it still works fine.
The last thing worth noting is that the little plastic sliding door that keeps the BBs from falling out of the storage chamber is very loose. This means that if you tip the magazine forward, unless it’s already inserted into your gun, the door will slide open, letting BBs fall all over the ground. Therefore, keeping spare magazines outside the gun (in a vest, backpack, etc.) is not a good idea without taping over the door first. However, this isn’t a huge problem because, being an already extended magazine, you may not need a spare.
In a wrap, the DBoys Extended Magazine is great for extended shooting. Even though you have to stop about half way through the magazine to re-wind it, it still beats having to carry a whole other magazine with you. And also just keep in mind that you might have to put some effort into getting the magazine into your gun.
Also note that this attachment is for AEGs (Automatic Electric Guns) only. It won’t work with spring rifles.