So guys I've been fighting to feed heavy BB's, particularly Ajax Customs .43g BB's out of my M16 "Sniper" project. I've tried all my mags without much luck. I did find that a short VN style 190 round hicap would feed them, and I've got an old old Star 30 round real cap that will feed them. I should also note these BB's are heavy, and they have a non-polished appearance. Normally that would be a bad thing, but honestly they are some of the best consistent heavy BB's I've used. I've been pretty consistent out to 100 yards and past with them, so the downside is they can be a bear to feed in magazines. They feed flawless in normal TM VSR10 mags. But when I built this M16 I couldn't find more than those two mags that would feed. And while 220 rounds is way more capacity than I would ever need with a "sniper" rifle, this gun has also fallen into a bit of a DMR role, where I'll do far more shooting with it. Several times I've carried loose ammo to reload on the field which I hate. And I forgot to mention the 190 round has to pretty much be fully wound to feed properly, which leads to allot of winding per several rounds. It's honestly not a whole lot of fun but it does work and it was the only option out of my 30+ mags that did work.
So to the point of this thread, last year I bought 10 midcaps off another forum used. They didn't work very well and I planned to tear into them and clean them up and see if I could get them reliable. They are actually single stack 68 round mags, not sure the brand wasn't listed in the sale. But they are metal 68 round mags, the plastic insert is hot glued in position and then held with the two tabs that stick into the slots on either side of the mag. When I was tearing them apart today I was a bit disappointed that they were 68's rather than 120+'s. But I had an idea, those heavy BB's only feed in single stack mags, double stack has too much weight and friction. But I also knew they didn't feed as they were so I'd need to make some change to try it. Now with this setup they will feed .43g Ajax custom's BB's flawless there is a downside though the change drops the capacity down to around 35 rounds and only 30 if you don't overfill.
The Mags:
So you take the magazine, and using a heat gun you heat the end of the mag that is all metal. This softens up the hot glue and allows you to remove the insides from the metal case. Alternatively you could soak the end in alcohol, I've read that alcohol will release hot glue very well, and I've been meaning to test that but I've never done it that way.
Then once the plastic insides are out you take the 5 screws out, then carefully open the inside halves trying to not loose and of the parts.
The insides:
Normally the spring routes all the way to the end, but note the guide rod lacking a better term is quite long in these mags. Long enough it's not going to make the bend on either end of the mag. Line it up in position shown in the pictures, this nearly doubles the spring tension while halving capacity. Then holding the spring in position with your left hand, the BB stop back in place and held in the rear half. Then gently angle the top half into position starting with the right then move your hand and close the mag.
At this point you'll have the spring going through the mag the right way, but around 8+ inches of spring hanging out of the BB feed hole which is fine. Then put your screws back in, leaving the two at the top nearest to the BB feed hole out a few turns. Then using your finger tips start feeding the spring into the mag body, pulling the BB stop back once in a while to allow it to catch the spring so it doesn't come shooting out. Keep doing this till you have about a half inch left, then put the BB follower back in place on the end of the spring push it down till it's up to the feed hole. Then gently pry the top of the mag apart wide enough to get the follower back in place without the spring popping back out. Then tighten the top two screws.
Toss a good dab of hot glue on the end of the plastic mag then quickly put it back into the metal case making sure it's fully seated before the glue sets. Then your all set and ready to go.
Really this is probably not an issue for allot of guys, and few people likely will be willing to forego the capacity to feed the heavy BB's. But for my particular gun and it's setup the heavy BB's make all the difference on long range accuracy. It's shooting right around 515fps with a .2g and like I mentioned above gets excellent range with this setup. And now with these mags I've got another option that will allow me some more mags.
I forgot to mention, I load these until tight IE overfull. Then I take 5 BB's back out one at a time, that's where I get 30 rounds capacity. I found the first five wouldn't shoot properly and you risk a jam which is bad news with an AEG particularly this type of AEG setup. So 5 gave me the first round working and feeding flawless to the end. For fun I tossed in some .25g BB's and it also fed in my M4 that is fairly high ROF build which normally will skip on most mags for me. I don't have ROF but if I guessed right around 30RPS so not crazy but enough my old mags can't keep up on auto.
Luke
