SpudFiles

Windshrike's comment here reminded me of a little project I had made a while ago to see the effects of high pressure in a BBMG. Since my only pressure source was a shock pump, I had relatively small chamber (that still takes me about 2 minutes of hard pumping to take to 400 psi) and used a piston valve built in the same way as my mini designs with an epoxy piston in a syringe tube.

It looks ghetto, I know, especially around the breech area, because it's been cut up and rebuilt many times - currently fitted with a 4.5mm I/D barrel for steel BBs, 15.5 inches long - but originally it had a 6mm airsoft barrel. With the current barrel it shoots an average of about 650 feet per second with BBs but is only good for a 5 round burst. as you can see from the damage pic, that's enough to embed BBs to a little more than their own width into a wooden plank.

edit: 5 round burst vs soup tin at 420 frames per second, the distinct impacts can be more readily discerned:

[youtube][/youtube]


dug it up and made a couple of videos:

[youtube][/youtube]

5 round burst through soup tin bottom


[youtube][/youtube]

5 round burst through soup tin side


[youtube][/youtube]

3 round burst through soup tin side

A "normal" BBMG (ie using typical compressor pressures of 100-120 psi) will succeed in chewing through a similar target, but in this case the effect is achieved using much less ammunition. A single BB at 650 feet per second is enough to fully penetrate 2 soup tins side by side and emerge with enough energy to dent a third can. Single shots from a vortex block BBMG at 110 psi will only dent the first tin. Note also in the second and third videos that you can distinctly recognise the individual exit holes of each individual BB as opposed to the "tear" from the action of many BBs at lower velocity.

however cool it may be, i dont think it would be much fun unless you find a better way to get alot of pressure.

the design itself is very interesting and i really like the gun, i dont think ive seen anything like it before.

edited to say that: i think you should call it "the combo gun" because it has a little of every type of pneumatic out there.

Very nice would you still call it a bbmg though even though it is 5 round bursts. Id agree it is pretty ghetto but still nice. This shoots kind of like a shot gun right. Correct me if im wrong. But it is cool though

i dont think it would be much fun unless you find a better way to get alot of pressure.

Pretty much why I forgot about it - now if only I could hook up a reg to my SCUBA tank, hmmm...

This shoots kind of like a shot gun right

Yes, but without the need for messy sabots and wadding

Really neat concept! Do you have to reload five more bb's each time you fire?

-goose_man

EDIT: Yay, 100 posts!

[quote="goose_man"]Really neat concept! Do you have to reload five more bb's each time you fire?

No, the bbmg fairies do it for him

goose_man wrote:Really neat concept! Do you have to reload five more bb's each time you fire?

No, the chamber holds about 20 BBs and there's an o-ring between the chamber and the barrel which is a little tight, meaning that below a certain pressure, the BB won't fire, which is why it's limited to 5 rounds per shot. It's having to pump it back up to pressure which is female lady dog of the opposite sex

edit:

No, the bbmg fairies do it for him

LOLOL, just like Chopper's magical elf called suity-packy hehe!

Novacastrian wrote:No, the bbmg fairies do it for him

I think that those BBMG faries are out to get me...

But anyway, really cool!

-goose_man

Very cool. You never cease to amaze me with your work with epoxy. Your a damn good artist and cannon maker with that stuff.
As I don't see anything to open to pour the bbs in, I'm assuming that you load it by pouring bbs down the barrel right?

it looks like something the cat dragged in
but you cant argue with results

As I don't see anything to open to pour the bbs in, I'm assuming that you load it by pouring bbs down the barrel right?

Yep

it looks like something the cat dragged in

lolol couldn't have put it better myself

very interesting if only it could be made more portable then it would be awesome.

f.c wrote:very interesting if only it could be made more portable then it would be awesome.

It's about as portable as they come in my humble opinion

Looks good. I haven't seen this yet as I don't look around in the BBMG section too often, but your thumbnail pic grabbed my attention when I happened to open it this morning.

BTW, I've got a scuba tank lying around in the shed. They'd be great for an application like this... if you had a regulator. One little jam or failure on your gun and it'll be filled with 4,500 PSI in no time at all. I've was looking for a regulator a while ago for it, but then my stepdad found out and said I couldn't touch the tank because he still used it. (It hadn't moved in years...) Maybe look on ebay for a small one?

Keep up the carnage. Eventually you're gonna invent something big and then the government might contract you to build small backup weapons that pack a big punch to pilots or some such.

Keep up the carnage. Eventually you're gonna invent something big and then the government might contract you to build small backup weapons that pack a big punch to pilots or some such.

is there anyreason why the governement wouldn't just give the pilots a pistol or a PDW like the H&K MP7A1 or the B&T MP9?

http://world.guns.ru/smg/smg49-e.htm MP7A1
http://www.mp9.ch/ MP9