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Helical Magazine
Posted: Mon Oct 22, 2007 1:41 am
by goose_man
I was just doing some work on building my fully auto 3/8" ball bearing pneumatic with a blow-forward bolt system, but I want it to load rounds fast (ie. not gravity fed), and I was thinking of maybe making a helical magazine for it to hold the balls.
Does anyone have any ideas, and possible advice before I venture out on this mission?
-goose_man
Posted: Mon Oct 22, 2007 1:44 am
by Novacastrian
Pull apart one of those cheap plastic cap guns and use the ratchet design they use. That or you could make it like an air-rifle 10 shot.
Posted: Mon Oct 22, 2007 1:49 am
by goose_man
I don't mean like a revolver. Here's a patent for this type of magazine:
http://www.freepatentsonline.com/5520171.html
-goose_man
EDIT:
http://www.qloader.com/ makes them for paintballs.
Posted: Mon Oct 22, 2007 2:02 am
by Novacastrian
Oh i see, rather i don't- have a clue how to help sorry old chap

Posted: Mon Oct 22, 2007 5:42 am
by goose_man
Okay, no problem. Can anyone else help; these maazines have a remarkable capacity for their size, and I'd love to incorporate one into my gun.
-goose_man
Posted: Mon Oct 22, 2007 6:37 am
by jackssmirkingrevenge
copper tube and curve it into a spiral?
Posted: Mon Oct 22, 2007 10:12 am
by goose_man
jackssmirkingrevenge wrote:copper tube and curve it into a spiral?
That wouldn't really be a helical magzine. In a helical magazine, there is the inner part which is basically 8 (or so) semicircular grooves going down the outside of the length of a rod. This forms a spoke-like shape if you look down it. This rod is on an axel lengthwise and a torsion spring (that's pre-cocked) will turn it.
The outer part is a tube that has thin rigid exdentations in a helical shape. The inner part is placed in the outer part so that the spokes from the rod (where the grooves are) barely don't touch the exdentations. Picture the ammo in this device, and as the inner rod turns the ammo will be forced up the helical exdentations until they reach the loading mechanism.
I hope that made sense. If not, read the patent I linked to and check out the paintball link.
-goose_man
Posted: Mon Oct 22, 2007 10:49 am
by jackssmirkingrevenge
A sort of paintball version of the
Calico pistol, hmmm...
Why not just
follow the patent drawings?
Posted: Mon Oct 22, 2007 11:08 am
by ShowNoMercy
Why not use a spiraled copper tube and have a pulse of air hit the end of it before the bolt opens after each shot?
Posted: Mon Oct 22, 2007 12:10 pm
by williamfeldmann
Does the grooved rod turn or does the auger looking thing turn? I would think the rod.
If your skill at machining is good, I would say try to copy the pics. The rod shouldn't be overly difficult to make and you probably don't have to make it doublestacked for simplicity. Are you going to use something similar to the paintball mags you posted, with a hose of sorts between the mag and the action, or are you going to have the mag feed directly into the action?
Posted: Mon Oct 22, 2007 3:20 pm
by goose_man
I'm going to have a bit of hose to connect it. Since the hose doesn't need to hold pressure, it can be just slipped on and I can fire away. Also, does anyone have a good idea for the torsion spring?
-goose_man
Posted: Mon Oct 22, 2007 7:09 pm
by ammosmoke
I don't understand why you don't just use a coil of copper tube, or even lubricated nylon tube and a long spring or series of springs. If you can find a way to lock the end shut with a tiny ballvalve or something you could just use a speedloader and fill it up. Don't make it more complicated than you have to...
EDIT:
Make that a coil of tubing inside a pipe.
Posted: Mon Oct 22, 2007 9:10 pm
by origin unknown
You could get a torsion spring from one of those Hi-cap airsoft mags. Just buy a few cheap mags on ebay and remove the springs.
Posted: Mon Oct 22, 2007 10:36 pm
by goose_man
ammosmoke wrote:I don't understand why you don't just use a coil of copper tube, or even lubricated nylon tube and a long spring or series of springs. If you can find a way to lock the end shut with a tiny ballvalve or something you could just use a speedloader and fill it up. Don't make it more complicated than you have to...
EDIT:
Make that a coil of tubing inside a pipe.
The helical magazine holds a lot of ammo and the spring could be a lot smaller than with your idea. Also, with that idea, the balls would put more pressure on the bolt when it's closed. The helical magazine only has to spin a few times (with a torsion spring that's real easy) whereas with a long spring forcing the ammo through a tube, the spring has to compress to many times smaller than its rest position.
-goose_man
Posted: Mon Oct 22, 2007 11:39 pm
by ammosmoke
Soo,, It moves like an auger? And the bb's stop it until they are fed into the gun... ahhh I get it now. Well, still, my design would hold a lot. Probably about the same per volume of pipe. Idk, in my mind my sounded better, but that is prob because I am biased about my own ideas lol.
Would this help?
http://www.tapplastics.com/shop/product.php?pid=154&