Spring Piston Rifle

[Crna Legija]

What is dangerous about the forces involved? I'm going to be getting a lathe and a mill so wall thickness and creating threaded plugs are no problem.

yeah but do you know how to use them you can just put a bit of pipe in there and tell it to cut m10 threads there's a lot more to it.


and i would say get the spring piston and chamber from a old motor bikes front shocks.

[jackssmirkingrevenge]

[pneumaticcannons]

If it reaches 70 MPH then this gun will easily shoot a pellet at 800 fps

What exactly dO you mean by that?
Also, converting FPS to mph is easy
Where FPS is "F" and Mph is "M"
M= (F*3600) /5280
Or
M= F/0.68

[Zeus]

Derp, what you described is how a gas ram piston works. Precompressed gas takes the place of the spring, I don't know where you got the ball valve thing from.

Anyway, ball valves have their place, pilots for instance..

[DerpWithAGun]

@pneumaticcannons I mean that if the compressed air propells the piston inside the chamber at 80 mph then that is enough force from the piston to then project the pellet at 800 fps.

@Zeus Really? You mean my last post on the first page? I didn't think that what I described there was a gas ram. I thought the home made gas rams had ball valves, geez I am so confused. It's on the link that Gippeto put on his post on the first page. In that thread there are all pictures of gas rams with ball valves. I was also very confused because it was stated in that thread that you can actually buy commercial made gas rams that go into your commercial springer. I'll do more research, thanks Zeus.

[Gun Freak]

Whats the deal with the sealing face you keep talking about?

[warhead052]

Derp, a gas ram is the same thing as a springer, but instead of a spring its pre-compressed gas that compresses further when you cock it back, then you pull the trigger and the same effect happens as with a spring air rifle.

[pneumaticcannons]

If ya have a 0.75 in piston traveling at 102 FPS (70 mph) it would theoreticaly displace about 8.5 liters a second. You need a displacement rate of at least 6 liters a second for a 0.22 barrel if you want that pellet to be doing 800 FPS. So with a 22 barrel and a 0.75 in piston traveling at 70 mph it would theoretically get the pellet up to 800 (actually higher) FPS if air was rigid...... Air isn't rigid lol. You will have to compensate with A barrel pretty much equal in volume compared to the cylinders volume ( actually the volume the piston displaces inside the cylinder)
Ugh... That was a lot to type on an iPod

[DerpWithAGun]

Alright then thanks for the info guys!

@Gun Freak the sealing face is on the front of the piston and it acts as a bumper and a seal....

@pneumaticcannons I understand what your trying to say. The only thing which I don't know what your talking about is the 0.75 and 0.22, what do they mean?

I'm gonna start drawing designs.

[Brian the brain]

Be sure to pump up that airspring with the gun COCKED.
Otherwise you will be compressing 1000 psi even further.

With a lathe and mill you can make the parts needed for a breakbarrel or underlever design without the need for welding.
You will need the mechanical advantage of such a mechanism to cock the ( air) spring.

It will be impossible to cock it in a linear motion.

I hope you reconsider your chosen caliber and go larger.
The small ones can be bought.
Whatever you do:
I would sure love to see this thing when it's done!!!

[Zeus]

BTB, not out here, without waiting a couple of months for a license, then 28 days for a PTA (permit to acquire), and you need a good reason for every firearm.

[pneumaticcannons]

Alright then thanks for the info guys!

@Gun Freak the sealing face is on the front of the piston and it acts as a bumper and a seal....

@pneumaticcannons I understand what your trying to say. The only thing which I don't know what your talking about is the 0.75 and 0.22, what do they mean?

I'm gonna start drawing designs.

Those are the diameters in inches... 0.75 inches and 0.22 inches

[DerpWithAGun]

@BTB It would be hard for me to make the parts for the break barrel as I don't know what they look like. I'm sure it will be relatively easy to create my own design, I probably will make a break barrel. And since you would love to see it done, I have just been motivated even more! And for the cocking mechanisim I could also make just a lever like a bolt action but it extends to both sides of the gun and I would cock like you would cock a compound crossbow; with two hands.

@Zeus Don't worry about getting ammunition, my Uncle has a license and he can buy me some .22 pellets. So does my friend who could buy me a dozen boxes of pellets if I pay him. (I'm not sure but do the gun dealers check in your file what guns you own and only let you buy ammunition that will fit into your guns???)

I'm going to make the chamber 250mm long, the outer diameter of the chamber will be 20mm and the inner diameter will be 18mm. Gas ram and piston size are TBA. Amount of pressure has not been decided, I am hoping I can get a pellet as close as I can to 1000 FPS using under 900 PSI in the ram. Time for some GGDT! (After I play some Battlefield 3 )

[Crna Legija]

(After I play some Battlefield 3 )

BOOOOOOO

everyone knows cods better

[Zeus]

(After I play some Battlefield 3 )

BOOOOOOO

everyone knows cods better

BOOOOOOO

Everyone knows the argument's stupid.


Fallout 3