Another update, and more box mag fun...
As I might have indicated earlier in this thread, I also have an A&K MK43 Mod 0 (M60-E4), and despite some serious reliability issues that had to be overcome which involved a complete teardown and rebuild among other things... That MG was a beast, or Pig perhaps
. One of the things that made it so effective in some of the situations I'm thinking back to was the massive box mag, at around 4500 rounds if I remember right. The larger capacity of the M60 and some Russian variants of MGs allow those weapons platforms to dominate positions with volume of fire. I know I've mentioned before that this MK46/M249 build is aimed at light weight and mobility, but I would like the option to pack more ammo for some milsims. Here, our rules for sims are that MGs can pack one full box mag, and does not differentiate on capacity. So I can either rock the 1500 round 'nutsack' box or 2400 round standard box. While the 1500 is fantastic for assaulting and mobility, I've always felt the 2400 round box was a tad wasted with only about 40% of the box actually contributing to ammo capacity and having 60% lost to internals when the nutsack mags can pack over half that for considerably less size.
I've been contemplating this since first disassembling the 2400 round box mag, and I finally pulled the trigger on my 'franken-mag' which holds an estimated 5500 rounds hahaha. My intention is to use this for milsims with more open area, less trees, and plenty of structures. The field I have in mind is entirely open area and structures. On many occasions I've bled the 2400 round box dry and been left with my pistol or running back to respawn to reload.
At any rate, I made this using 1x A&K 2400 round box and 1x A&K 1500 round box. The construction is fairly simple and involves splicing the internals of the 1500 round box into the 2400 round box shell, splicing the feeding tubes together, and rewiring...
So here's the comparison of the two boxes, brand new:
And here's a couple shots of the internals. Virtually the same parts in difference configurations.
After test fitting I used my dremel to remove some plastic that was in the way, although it fit extremely well right from the get go.
To fill the void left by the smaller width, I cut some foam and hot-glued it to the internal mechanism to keep bbs out and keep them rolling to the mechanism. It's hard to see in the picture but the top is tapered.
Since the spring feed tube on the 1500 round box mag isn't long enough to make it to the magazine insert without stretching horribly, I cut the spring and used some extra plastic tubing I had laying around to connect cut spring and the left over spring from the 2400 round box. After bridging them (already snug) I used a heat gun to warm up the tube and then clamped down on it to get the semi-melted plastic to mould to the spring so it could not slip out.
And then a test fill. I had estimated it would hold around 5000, but after filling it completely with a brand new bottle I'm estimating around 5500 now.
After that I disassembled again and re-wired it. To secure it in place I used four of the screws securing the fabric on the 1500 round box to the plastic and screwing the top and bottom pieces together. I used a 1/8" drill bit to pre-drill the holes then fired in the hex head screws. Lastly it saw some paint to match the camo scheme and was tested. I'm quite happy with this project and if you need some more firepower it's relatively easy enough to do with some patience and know-how, although it is quite expensive for what you get considering you have to buy two box mages and then combine them into only one.