I gave this product a low rating for several reasons which I will discuss. I am using these mags with my KWA M4 CQB. When I was considering purchasing these mags I heard that they do not feed well into Classic Army M4s. I was concerned about this so I called up Airsoft GI and spoke to someone there. He was very cool and actually went and tested these mags in a KWA. He came back to the phone and said that they fed perfectly with no problems. I asked if they fell out of the gun when you pushed the mag release and he said yes, they do fall out without having to pull on them (something very important to me, since with standard-caps you need to be able to reload quickly). I was totally impressed by the customer service and went ahead and bought these.
Unfortunately, either my KWA is completely different from the one that I own, or the information I was given was false. First of all, these do NOT feed consistently into the KWA. On single-fire, then will fire one round, then nothing. You wiggle the mag around and can hear it *click* when the BBs feed in. Then fire again, one round and that's it. Now on full-auto, they seem to feed a little better, I guess because they move around from the recoil of the spring in the gearbox.
The second problem is that they absolutely do NOT fall out of the gun by themselves, in fact they take a great deal of effort to remove. I would actually have to stick the stock of my M4 under my armpit, hit the mag release, and YANK them to get them out.
I was able to fix both of these problems with some modification, which I will detail for you in case you need the info. First of all, the feeding problem. As I examined the situation I realized that the mags were not feeding because the BB catch (not sure of the technical term, but I'm referring to the spring-loaded part that holds the BBs in when the mag is not in the gun) was not being released fully by the feed tube (the part in the AEG that feeds the BBs up into the gun). It was releasing the catch, just not all the way. So what I did was remove a VERY SMALL amount of material from the tip of the catch, the part that actually holds the BBs in (using a dremel tool with a narrow carbide milling bit). This way, the feed tube only had to push down on the catch a little ways for the BBs to start to feed. This seems to be working perfectly in the one that I modified and I'm going to do it to the remaining nine shortly.
Now on to the mag release problem. I determined that the cause of the mags being so tight was that they are a little bit too wide at the back, nearest to the trigger guard when loaded into the AEG. I took my trusty dremel and removed, again, a very small amount of material from each side where it was too tight. Just a little bit was all it took and now the mags fall out by themselves just by pushing the mag release button, allowing you to slap another mag in quickly.
So, now after the listed modifications, the mags works perfectly :) However, for the price I paid I wish that they worked perfectly right from the factory.
I will say that I really like the fact the the P-mags are a little different than normal M4 mags, which helps keep them separate at games because they are unique. Also the caps on the bottom of the mags really help you to grab them in a hurry. That said. the ribbing on the sides of the mags cause them to catch on each other when two are stored in one pouch (as they are in my vest, two per pouch), and that causes problems sometimes. One final point that I love about these mags is that they actually hold 33 rounds (yes, I counted :) ), which is great since as most of us know, three rounds are normally wasted. So instead of only feeding 27 rounds into the gun, it actually feeds a full 30 rounds for realistic mil-sim use.
FYI the mags are plastic construction, but seem quite rugged.
I would NOT purchase these mags again.
Unique look, feeds a full 30 rounds into the gun.
They do not work well "out of the box" in KWA rifles, or CA rifles from what I have heard (no personal experience).