3mm BB cloud + barrel idea

[Carlman]

Hi all,

Recently i took apart some old bike parts to find some bbs to make a shell for my pneumatic shotgun. When i took apart the pedals of bmx bike i found that it used loose 3mm ball bearings. I inquired at a bike shop and they said they could get me some at the prices they get them for. My question is has anyone on here made a cloud bbmg using 3mm bbs as ammo? and if so a link would be great.

Also whilst in my shed i came across my torn up tent, its an old dome tent with wind damage. The poles that suport it are the type that are held by elastic and they spring together. I cut the elastic and found the best barrel for the 3mm bbs! Stong, light, perfect fit what more could i want.

So yea sorry for the long post but i wanted to hear comments and to see if others have attempted 3mm cloud. thnx.

[POLAND_SPUD]

IMO it can be done but it's not worth trying - a 3mm projectile would have max range of < 100 ft. because the lighter the projectile is, the faster it slows down....

[Carlman]

im not going for range here just really small holes in stuff

I live in oz where bb guns (and everything else on this site) is banned, so this is the cheapest way for me 2 go.

I was also thinking of making a spring assisted ball valve pneumatic with the 3mm barrel and using a short 15mm chamber just as a single shot gun. call it a very small, very fast plinkler lol

I dont know yet what i will do it depends on how many bbs i can get vs the price.

[POLAND_SPUD]

go to your bike shop again and ask for bigger balls or try somewhere else... 6mm would be ideal for plinking...

use a blowgun as a firing valve, ball valves are very akward to use on minipneumatics and they have very poor performance, especially with light projectiles...

[Carlman]

but would ur everyday blow gun have enough flow to get semi good fps?

i would of thought a larger ball valve spring actuated would be better

[POLAND_SPUD]

a blowgun has enough flow for 6mm and it's easy to use

[Carlman]

so if i used the 3mm it would be plenty then?

what kind of fps would i expect from a 30cm barrel with the compressor regulated at 80psi?

[Infernal Maveric]

I can work all that out for you with GGDT if you like?

I'm not sure if 3mm has been done, but I know JSR has made a pen-sized pnuematic gun which shot tiny lead shot.

It can be done and would be a good alternative to shooting x-mas decorations as ammo for the OZ spudder.

EDIT:



Right there for you mate. I had a burst disc as an input as I wasn't sure if generic" means blowgun as the valve.

[Rainman]

the easiest way to make a pneumatic gun is to get the barrel you want and wrap it with paper on one end until it is about 12 to 15mm diameter(then a wrap with rubberized tape like duct tape for grip) and stuff it in the barrel of any kind of nerf gun(make sure it is tight and snug). With the spring nerf guns there is a button in the back of the barrel that needs to be pushed to fire, so be sure to push your barrel back all the way. I do this with airsoft all the time. I make my barrel out of paper too by wrapping paper around a long k-nex piece(exatly same radius size as airsoft), though this is not recommended for good performance.

[Infernal Maveric]

What on earth are you on about Rainman?

[jackssmirkingrevenge]

I'm not sure if 3mm has been done, but I know JSR has made a pen-sized pnuematic gun which shot tiny lead shot.

JSR actually used a 2.5mm barrel and found that even with 300 psi and a piston valve, the lead shot was barely able to penetrate a sheet of paper.

However, as a BBMG it might well work - most BBMGs have woeful single shot power, but with a good rate of fire that translates into serious damage. I would recommend using something longer than a 12 inch barrel though.

IM, there's no way a 3mm ball bearing weighs 5 grams it's more like 0.1 grams for steel. I redid the GGDT math, less than 1 ft/lbs for a 12 inch barrel, but upping barrel length gives almost 600 feet per second, very respectable and almost double that of the 12 inch barrel, meaning 4 times the muzzle energy per shot.

[POLAND_SPUD]

yeah JSR but it is still quite weak and he can use about 80 psi....
With a 3mm barrel he is limited to ball bearings because it's hard to find something small enough to fit in the barrel... - 3mm might be cheap but he wants to make it a BBMG and this is going to eat a lot of ammo
one important note -> It's difficult to reuse normal BBs because they are so small and difficult to find after shooting - I imagine it would be much more difficult with 3mm BBs.


I think this 3mm idea is not practical... all he needs is 6mm semiauto gun to shoot stuff... A 6mm barrel and a blowgun that's all he needs... then he can modify the blowgun or upgrade it to BBMG whenever he want's to

[Mr.Russ]

if you want to stay with the whole metal ball bearing ammo thing in aus, all i do is pop into big W or kmart and buy some sinkers. if you dont know what size to get, measure the ID of your barrel, and then use a ruler from stationary to measure the sinkers.

[Carlman]

312ft/second aye jsr, tht aint too bad is it?, what if i were to have 20mm endcap joinng onto a male thread > 20mm ball valve (spring actuated) >male thread> Reducer> epoxy reducer> barrel?

Then just make it a single shot, or would this make the barrel become the projectile, or if not 20mm what size?

and just make it a single shot, would it be more powerful?

MRRUSS: my mates got me banned from big W last year

hate them!

POLANDSPUD: dont want a bbmg anymore as ammo could be expensive from bikeshops.

INFERNAL MVERICK: haha christmas decerations, mite hav to try that. Nd yea shud be fun if worx out.

[jackssmirkingrevenge]

If you're making it single shot, then a blowgun would be sufficient as a valve - I find blowguns have sufficient flow for a 6mm barrel, so a barrel with 4 times less area should be a doddle. You would of course lose the multi-shot benefits of a BBMG, meaning you'd want a lot more velocity out of your projectile - so if I were you I would look into getting myself a MTB shock pump and finding materials rated to 300 psi or more (your fellow Aussies on here will help out I'm sure, particularly Mitchza89 ) as well as using a long barrel as suggested earlier.