SpudFiles

MB2 (Marble Blaster II)

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Here it is, my second pneumatic gun, only two weeks after I finished the first one :

* as I sead, it is pneumatic
* made fully out of metal (copper)
* uses barrel sealing piston valve
* pilote valve triggered by a 3/4 balvalve
* dual chamber 34 mm copper pipe
* rest of the gun is made at 28 mm copper pipes and pices
* pressurizing valve is a bycicle tire valve
* C:B ratio, depends on the barrel type, at least 2:1 with the 34 mm barrel
* it has exchangable barrels, 10 mm, 15 mm, 18 mm, 22 mm, 28 mm, 34 mm and a 1 inch galva barrel

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Ammo : about everything I can lay my hand on
For starters I use marbles, both small ones (16 mm) and big ones (26 mm)

I testfired it, and it leaked at the piston valve. So I changed the rubber, nog it is ok. I could only testfire it at 100 psi, dont have more pressure untill my high pressure pump is ready.

Here the damage pics :

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and a pic of the actual test fire ammo

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Me holding the gun, so you can see the size :

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Improvements since the MB1 :

* shorther space between the piston valve and the ammo
* bigger chamber
* better piston
* ighter than a galva gun

What still needs to be done :

* make a wooden stock
* make a wooden handgrip in front
* give the whole thing a paintjob (will be non-shining black)


Now some questions :

What about this gun, you like it ?
What can I do to improve ?
At what pressure you think I can shoot this one ?
Do you like the concept of the twin chamber in this gun ?

Edit : forgot to mention the cost : about 100 euro.

I like it man and I love the ammo. What kind if rubber are you useing for the barrel seal ??

rubber from a bycicle tire

The inner tire that is

wow nice copper gun,if you put a wooden hand grip on you should get that grip paper stuff that you find on rifle stocks at the front

Nice,but the pics are a little small to see the in good detail.And yes i like the twin chamber and i wouldnt be afraid to take it to 250psi 17bar.

Thats why you click on the pictures.!!! loverly gun ya got there, any idea on distance?

Haven't tried distance yet. I live in the woods. Lots of trees here

Ok, the gun is completely finished now. Got some pics and damagepics, enjoy :

this .....is............mmh.......AWESOME!!!!!!!!!!!!!!!!!!!!!

mm where did you get those 34 ( I think it should be 35??) fittings and pipe??


If I could get that I would defenitely redo the old sawed-off in 35 mm!!!!

Man!, that is really cool! I really love the stock, it gives the cannon such a threatening yet awsome look.
I think you should try make that as tough as possible, by renfocing the chambers. Great work

Brian the brain wrote:mm where did you get those 34 ( I think it should be 35??) fittings and pipe??


If I could get that I would definitly redo the old sawed-off in 35 mm!!!!

I only fount it in 1 do-it-yourself-shop. It is 34 mm indeed. I bought reducer parts, from 34 to 28. At least I tought so. It was actualy 35 to 28 mm. So they didn't fit. I had to made them fit. I couldn't find endcaps eighter, so that's why there are reducer parts in the frontside of the chamber. The twe chambers are solderen together in front, but not connected like air-wise. The chambers are pretty stong, no wories about that

The stock is very strong to. I had much problems and had to work really hard to get the steel in this form.

I just tried a distance shot. I put up a target, a wooden plate (the second plate in the above pics) up to 25 meter, halfway my driveway. In front of it, I put the first plate from the pics above. I lied down at the door of the house, aimed for the top of the plate, cause the bullet always drop in his flight (I used a 25 mm marble) and shot the target at 8 bar. (110 psi) I didn't even hit teh first plate. The bullet only dropped a couple of centimeters, hitting directly on the second plate, en flew clear trough (nice round hole, and major damage on the backside. After I heard it hitting the wood, I heard a 'ting'-noice. The bullet flex further of course, hitting the steel gate. I went out to see if the gate was dammages, and unfortunaly it was. One of the vertical steel pipes had a dent in it. The gate was 50 meters away from the gun.

I was very pleased whit this performance 8)

Now I just need some sort of sight to get a bether aim.

wow that looks sweet nice damage pics and i like what you did with the stock, is that a first in the spud-gunning world?

Dont know, would be niuce though.

Got a question about the GGDT. The weight of the projectile is in "gm" What on earth is that ? I know mg (milligram), but that sure aint'it.

And does someone know the weight of a 25 mm marble ?

Brian the brain wrote:mm where did you get those 34 ( I think it should be 35??) fittings and pipe??


If I could get that I would defenitely redo the old sawed-off in 35 mm!!!!

I can get 32mm Pipe, Thats what I used on the chamber for Heavy Artillery and the now compleated Hunting rifle.