we g36 drum mag
 

hello ladies and gents,

after recently becoming the owner of a WE g36c, to replace my m4, i decided i wanted to upgrade it to a full sized mg36.
(if the mg36 is its name or not i dont care, theres a thread for that somewhere already)
but after hearing that WE and most likely other manufacturers will not be producing a gas drum i decided to make one myself.

i have my basic idea of the parts i need made however i wanted to see if anyone has had any experience with the sites
that take your CAD designs and then send you the machined parts e.g. emachineshop.com

are you planning to make an external air source ?

im currently planning in internal source, due to the design of the we g36 mags and there 3 parts my idea is to take the original top part and add custom parts below it and fit it into the drum mag

well, thats just what I think so don't quote me on that but:
an LMG fires a lot...like....A LOT, so wouldn't the internal source cause too much cool down ? The only GAS LMGs I ever saw where all external air source

yeah, it depends on how many rounds you are planning on carrying in the mag. A saw has 2500 rds at it's disposal for a reason, and even if you are shooting for the real cap 100 rds, you'll be hard pressed to get the gas you need to fire it in the mag. I'd suggest moddifying an existing mag to an electric winding cmag, and exchanging a feed valve for an external gas tank

i did think about the cooldown, for the lose in efficiency i wont be going around hosing all the time, just burts. however if because of the larger capacity of gas it still coolsdown alot i will see about a highflow valve

With an external air rig, cool down is less of an issue and gas for a 100BB is going to be hard to fit in an internal gas tank within the drum mag.

4 x the gas capacity to fire 100 rounds certainly seems within the realm of possibility. Feeding , should not be an issue , there are lots of midcap mags that carry more than 100 rounds.

and contrary to what some may say.. you don't need a boxmag of 2500 rounds to be a support gunner.

Don't listen to the neigh-sayers, see if you can do it!!

I have been working on one for the past month for my M4, basically I have one drum with a cylindrical tank holding propane, and the other with drum with the feed.

I took a long rectangular plastic tube, heated it up and bent it so it spiraled into the left drum. I don't have any special parts, just used an old CO2 mag and the external shell of a DBoys BETA mag.

thanks for the support

i also have a dboys mag on the way for the basis of my mag, with you pipe for the bbs how well do they feed with the almost 90 degree from the drum portion to the upright mag

There is quiet some space between the dram and upright mag, I have a nice 3-4cm radius curve going through to the top.

For the cooldown there is an obvious solution :
You have plenty of space in a C-Mag so you may do like on the electric model store BB on one side, on the two it would be a serious pain in the ass I think, and put the gas tank on the other half (or both sides actually). Because of its size you may be able to use either multiple CO2 pellet or more interesting in my opinion : make the wall and seal thick enough for to be filled either with the Madbull tool (still CO2) or the best : use a compressor to fill it with compressed air.
Then bye bye cooldown ;)

Would a 3.5 ounce tank fit transversal?

http://www.clevelandfx.com/images/grapgun/CO2.jpg

im thinking of filling in half of each side with a chamber that will fit up to the wall of the platic mag to balance the weight then theres room for the bb feed tube but still lots of capacity

whats the height on the tank?

Well that's a photo I pulled off Google, but IIRC under 4 inches?

The ASA thread is .85 inches wide, plus the red thread protector gives about 1.25, more or less three times that large total eyeballing.

could work if cooldown becomes an issue.

heres my afternoons work on CAD, just rough lengths right now waiting on my mag in the mail.
http://i271.photobucket.com/albums/j...fud/magcad.jpg

Best solution would be to have a gaz reservoir machined to fit on one side, and build a simple coil/spring feed tube on the other side. There is enough space to fit over 500 BBs in a tube. The mag you have ordered can be taken appart, the center "mag" section is removeable. You would need to modify the existing mag to fit a coupling near the strike valve, and run a line from the coupling to the reservoir. That would also act as an expansion chamber if done properly and will help with the cooldown. There is enough space for 100-150 rounds, maybe more if you use CO2.

And that 4oz bottle does not fit in any dimension in the mag. The drum is the same depth as a regular mag. The round sections are about 3" dia.

Errr... I think the point of that thing is not to hold as much rounds as possible, plus 500 hundred is way too many for a tank only half the size of the mag.
I don't know for you bu I'd rather change C-mag and put a new one in than refill the tank in the middle of battle.

there arnt 500 in a real one, im thinking around 200-250 more than normal but not silly.

anyways drum mag is in and gutted already. if anyone needs spare dboys drum mag parts let me know. working on a design for the gas chamber on one side and bb the other. pics later on

Please do keep us informed this sounds interesting!

well after making my initial designs the emachineshop site wants over $300 for the parts even as abs prototypes. would anyone be able to point me in the direction of other similar sites? thanks

i had some prototyping work made with these guys. http://www.novaproduct.com/ .. i dont think it'll be any cheaper, but it's nice to have options.

Prototyping usually costs a lot more than mass production, nothing surprising.
My rifles prototypes with carbon barrels cost me 5000$ each (5 in total). The 5 mass production ones were made for 2300 a piece.
Nothing surprising with your 300$, I don't think you will get a lot cheaper unless you know someone working in the field who can make it for you.

il check them out. there stuff is more reasonable when you just get it made right from aluminium but making all the small adjustments so designs can be made by them is time consuming. oh well if it works maybe i can mass produce the parts for less :D

You have a taker right here :D

probably make alot too seeing as we wont be making em lol

http://i271.photobucket.com/albums/j...ud/drumpic.jpg
okay heres the latest design for the tank, it will snugly fit into the left side of the mag and leave the right for the bb tube. i have a matching cap that will fit into the top also. the lip at the bottom right is the same dimensions as the bottom of the upper part of a standard g36 mag so its as simple as bolting the two together, no need for a custom top.
currently looking at just a little over $200 for both parts it includes shipping but i will have to put it on hold for the moment :(

there in country for a start so a little saving on shipping :D

If I may : make the bottom part a little bit thicker, at leat 4 mm of contact for the seal to be effective and not that 1mm crap WE puts in the mags.

this g36 mag piece has 4mm already unless im thinking of the wrong spot

Well I was thinking on a GBB pistol-like construction : one screw in center of circle part and a plate closing it by putting pressure on a massive seal.

i think i see where you mean, makes sense seeing as its holding more gas.
anyways heres what gave me the idea:
YouTube - C-MAG仕様M4　GBB 　WA　ガスブãƒÂ*ム¼Ã£Æ’Â�ック　WAM4

tried them out but they want $600 dollars for the one piece guess not saving on shipping

Ouch !

A C-Mag should be around 200/250$ in mass production I think, your 300$ for prototyping are pretty fine. Plus it's a pretty easy one to do.

One thing though : because of the forces applied on it you should consider putting a screw on the middle bottom part, under the magwell.
Even if not pot metal I fear there might be an issue of the part bending under pressure.
So three screws : two in the "nuts", one in the middle.

i plan on using the original screw to attach the upper mag part to the tank and then two through the cap to hold it on, ive made small changes since the last pic. $300 now seems reasonable compared to the in country work, which is a bummer im a big supporter of buying in country. are there any machinists out there looking to make some bucks?