TVBA-BBS

[SniperMan]

Cannon Name- TVBA-BBS (Triple valve, Bolt Action BB Sniper)
Type of Cannon- Pneumatic
Chamber Size- 50mm X 25cm ~700cc
Barrel Size- 7.5mm bore, 600mm long (7mm bb's)
Gas Source- Air Compressor @ 80psi
Valve- Machined aluminuim Piston valve with silicone seal. Actuated by a pneumatic solenoid valve - Permanently connected to air source, no need to 'recharge'!

Other Special Details:
Barrel is a 7.5mm aluminium tube sleeved in 1/2" copper pipe. I chose this design to create a bolt type mechanisim for loading bb's.
Magazine is contructed of 1/2" brass tube and holds 16+1 bb's
Rare earth magnets on either side of the barrel hold the bb in place until fired and also help with pulling bb's from the magazine
Scope is a Tasco 3-9X40 with laser assitance and backlight sight
MEASURED muzzle velocity of 152.6m/s @ 100psi (500FPS!) using home made chrono (IR led/reciever pair from mouse hooked to sound card)
Can generally group 10+ bb's within about a 3cm circle @ 15m

Currently working on:
Silencer... To be completed in the next day or two!

>>Video here!!<<

[ProfessorAmadeus]

That my friend is TOTALLY AWESOME!! Thats really cool that you get to use ballistic gel. Isnt that really expencive?

[SniperMan]

It's the 'poor mans' ballistics gel.

Get 9 parts water to 1 part gelatine by weight, mix it up, throw it in a container, let it set (in the fridge) for a few days and voilla!

There are official gels and they are more controlled etc. but they are still just gelatine. Buggere'd if i'm gunna blow $300 on some gel for a bit of fun.

This mix is still probably 90% accurate to the real stuff.

[singularity]

where do you get 7mm and where did you get your solinoid valve. very impressive gun, a true sniper 8)

[SniperMan]

the 7mm bb's were bought off ebay. The person i bought off did not list them, i had to ask then he done a tailored auction for me. He sells other bulk lot ball bearings tho.

Price at the local shop was 37c ea. These were 7c!!!

The solenoid valve is by SMC i believe. Festo also make similar vlalves. Not sure where you could shop for one. I can get the exact model of the valve if you like. I have one spare too if you want it (depending on location)

[saladtossser]

love that awesome realism

[SniperMan]

That is sorta what i was going for. I wanted something that was aesthetically right, not a big thing of tubes and stuff. I think i done a reasonable job of achieving that.

[SpudStuff]

Would Jello Work?
Oh ya, nice gun what kind of speed you gettin'.

[beebs111]

maybe the plain flavored kind............

[SniperMan]

You want plain old gelatine. Not dessert 'jelly'. Look for it in the cake decorating bit of your local shop.

If you read and not just looked at the pretty pictures you'd see i get 150m/s or 500f/s

[experament_u2]

very nice gun and the ballistics gel is a brilliant idea I think im going to try make some today

[MrCrowley]

where do you get gelatine from?love the gun,damn you and your machines i would kill for one not that i can use one anyway.

p.s heres 300spudbux

[SniperMan]

Thanks for that.

Silerncer on it's way... Got 90% of the parts now.

Going to be nice polished aluminium when done. Just have to machine up the two end caps.

Remind me again but i believe i'm not allowed to post plans?

I just got the gelatine from Woolworths...Cake decorating part... $10 worth should sort you for about 2 of the ones in the pic.

[MrCrowley]

you can post plans,alot of people do to ask whether the design is effecient/will it work.post your plans if you want you wont get in trouble.

[SniperMan]

Ok, i'll take some pics of the bits tomorrow and post them along with the theory.