Stick batteries in m4 buffer tube?

[davedawg123]

Has anybody tried using stick batteries in an M4 buffer tube? Specifically, I'm curious what stock positions I would lose if I chose to go with an 8.4v 1500mAh 2/3A stick for a G&P standard 4-position buffer tube. I realize firefox 11.1v lipos fit, but I'm not looking for crazy ROF.

[pandemonium808]

i've tried it on mine and i found that the battery is just about .5 inch too long with the stock being fully extended. that is why i have this huge battery bag on the side of my stock.

[MDK_Marshal]

It's possible to make a custom mini pack fit, depending on what stock you've got. I've got a CRT stock on my M4, and as it's a bit differentley shaped to, say, and LE stock, there's room in the back.

 

Three cells in the buffer tube and four in the back of the stock. I lose two positions, IIRC - all the way in and the first one after that.

[davedawg123]

A CTR stock is exactly what I'd like to use. Are you referring to a 2/3A 7 cell stick?

[D-day]

I found this while moding a RS Vltor stock for a battery.

 

 

 

http://64.233.179.104/translate_c?hl=en&am...l%3Den%26sa%3DG

 

 

 

You can order a custom pack like this form cheapbatterypacks.com just tell them what you want and link a picture an you can have it about a week for a good price.

[davedawg123]

I saw that before. Trouble though is that RS buffer tubes (as used in that article) are slightly larger in diameter, IIRC. I'm pretty sure it wouldn't fit in airsoft buffer tubes.

[D-day]

Your best bet is trying to make a battery small enough to fit in a airsoft buffer tube. The website I listed has specs for the individual cell sizes, so you might be able to design one that fits using more conventional batteries.

[Belladonna]

i run a 8.4 stick in the stock tube of my m4....

LE stock, and 6 pos tube, it is flush with the end of the stock, and a buttplate covers it, no movement obviously, but a 4 is shorter, i doubt it would fit....

 

[davedawg123]

Your best bet is trying to make a battery small enough to fit in a airsoft buffer tube. The website I listed has specs for the individual cell sizes, so you might be able to design one that fits using more conventional batteries.

 

I realize that. I have done plenty of research in terms of cell sizes and discharge rates. 2/3A is about as short as they come in terms of high discharge NiMh/NiCd. I'm looking for examples from end users.

 

[MDK_Marshal]

A 2/3A 7 cell pack will fit in a buffer tube and CRT Stock. Gota make it specificaly for it and mod the stock a bit, mind, but it fits.

 

Basically, what you're after is a stick of three cells in the buffer tube, wired up to three cells in a triangle shape with one stuck on the end. Basicaly, the end of a "normal" 7 cell pack with an extra cell added on top of it.

 

Once you've got that it'll fit in the CRT stock once you chop out some material from the inside back of the stock.

 

It's a damned tight fit mind.

[Belladonna]

or you can fit a normal stick pack in the tube on a 6 position tube.... intact?

 

[MDK_Marshal]

Meh. I prefer to keep some of the slidey, as I prefer the stock not totally extended.

 

Plus I was bored and had a pack to butcher. Go figure

[davedawg123]

A 2/3A 7 cell pack will fit in a buffer tube and CRT Stock. Gota make it specificaly for it and mod the stock a bit, mind, but it fits.

 

Basically, what you're after is a stick of three cells in the buffer tube, wired up to three cells in a triangle shape with one stuck on the end. Basicaly, the end of a "normal" 7 cell pack with an extra cell added on top of it.

 

Once you've got that it'll fit in the CRT stock once you chop out some material from the inside back of the stock.

 

It's a damned tight fit mind.

 

I don't suppose you could post some pics of the mod and custom pack? I'm very interested in seeing the end result. I don't have a CTR stock on hand with me at the moment so I have no clue where the triangular piece would fit.

[MDK_Marshal]

Of course! Photos are below, hopefully it's fairly self-explanatory...

 

The whole pack

 

The "hump" on the end

 

Shown next to the stock

 

Recoil pad thingy must be modified like this

 

 

There are four rails on the inside that have to be cut down; they've been cut off halfway down the stock, as shown in this picture. Excuse the hole in the bottom right, that was me being a bit silly and screwing something up

 

Pack inserted in the stock - it's a very tight squeeze, needs filing and sanding of the inside of the stock to get it to fit

 

Side view of the "hump" in the rear of the stock

 

Battery in the stock, with recoil pad attached, and the stick of three cells poking out the back. The small stick can be pushed all the way inside the stock, and goes inside the buffer tubewhen the stock is on the gun.

 

 

 

Bear in mind that this was a battery I whipped up in about a half hour, and with the junk I had in my drawer - as such, it's not terribly neat, and I'm pretty sure I've damaged one of the cells while making it =/ If you're confident at assembling packs, or if you get someone decent to do it for you (cheapbatterypacks.com may be a good bet) then it may well be a battery solution that doesn't need LiPo's!

 

Oh, and the butt plate/recoil pad/whatever needs to be modified so it can sit flush with the rest of the stock. There's two little clips that need to be removed for starters, and a bit of material must be taken off, or it interferes with the cells.

[davedawg123]

Brilliant!

 

Is this the furthest the stock can be collapsed? If so, that's perfect for me.

 

If I asked CPB to custom make it, do you think the plastic/shrink wrap would be too thick to fit that triangular piece in the stock without having to enlarge the guts/ sand it down further?

 

Is that a real deal CTR or clone? I have a clone on its way to me and I'm curious if its recoil pad is removable.

[MDK_Marshal]

Glad it's of help =D

 

That is the furthest it can be collapsed - I hadn't meant to put it there, but it is! =D The stock doesn't lock all the way on for some reason (my buffer tube, I think), and this is the first position it locks in.

 

I don't actualy have a screw for the stock, and the buffer tube is held in with friction, but it should work fine with a crane-type setup. As for where the plugs go - I'm afraid you're on your own there. This is, as I said, thrown together quickly, and as such I have a mile and a half of spare wiring knocking around in the buffer tube, and a lot on the end of the pack. To be honest, the best place fr the connector would likely be between the two lots of cells, as that'd interfere with the cells in the buffer tube the least.

 

 

Unfortunately, I'm gona have to say yes, it would have to be sanded down - I had to sand mine down to get it in there, at any rate. Once you remove the rails inside the stock the bottom part of the triangle (with the extra cell on the end) fits in without too much trouble, but the extra cell on top needs sanding to get it to fit. I ended up taking my soldering iron to the top of the stock and melting a channel for it, and it's STILL damned tight.

 

If it's in heatshrink, though, it should be a better fit, as a couple of layers of electrical tape are likely to do a worse job of holding the pack together, and will probably increase the diameter of the pack by more than a bit of heatshrink.

 

And, finaly, it's a clone CTR. The recoil pad is indeed removable, it's screwed in with two hex bolts on the back and two clips at the top, which I removed to let it fit on with the battery inside the stock.

 

My stock also came with a plastic part to plug the hole at the back of the stock, but I much prefer the recoil pad being on there, it's much better to shoulder IMHO.

[Belladonna]

take a hacksaw, and cut about 2mm down off the bottom of the back of the body, so the tube, is now a incomplete, with a hole at the base.... wires go in there, tube goes on.

 

Now take the washer that goes in the tube, you can get pre cut ones, but its easy, take a third of it off, so theres still the centre ring entact, but the washer is now almost a D, bung it all in around the wires, hey presto, stock on, secured, and wires fitted....

 

or you could get a crane stock stock tube which has a D style washer and a pre cut channel in the tube itself to take wires.... they work a treat

 

[davedawg123]

Even with the 2 clips on the recoil pad removed, does the pad still stay on there okay? Or does it bulge out at the top

 

Will the plastic part covering the hole still fit with the battery there (so I could still have the back covered when not using the recoil pad)?

 

And is it possible to retain that stock position if the battery was reconfigured to a 4 cell stick + 3 cell triangle?

[MDK_Marshal]

Pozzie: I know that lot, I had to modify my receiver to fit the wires in and around it! Cheers for posting it though, it took me ages of searching to find that, and if it's in another thread it'll be easier to find in future

 

Davedawg:

 

Yes, no, and maybe, respectively.

 

The pad is held on fine by the screws, but the plastic bit simply plugs the hole in the back, adn is only held on by the two plastic clips on it. I had top remove these from the recoil pad, as they interfered with the battery, so chances are the plastic plug wont fit

 

As for the different cell config - it might do. I did tinker with other cell positions, but I seem to recall that the four + triangle ended up with it not quite locking in. However, it'll depend on your buffer tube, and the locking positions on it. Unfortunately, I have no clue as the the brand of MY buffer tube, so I can't let you know which one won't be of use* >_<

 

EDIT: * = In that config

[davedawg123]

Thanks. Is your buffer tube 4 positions or 6? I know for my G&P 4-position, the difference between pos 1 and 2 is ~1.75" (4.45cm). Comparing it with yours, do you think I could preserve pos 2?