SpudFiles

ok, I changed a very few things on that design, mainly making it 120 psi instead of 100, and got 271 fps, 7.6 ft. lb, That's not that powerful, my sniper will do that same velocity at 60 psi, and I'm looking at a co2 pistol right this second, and it does 410 fps....then again, it's .177

add a qev valve and you are set

maverik94 wrote:ok, I changed a very few things on that design, mainly making it 120 psi instead of 100, and got 271 fps, 7.6 ft. lb, That's not that powerful, my sniper will do that same velocity at 60 psi, and I'm looking at a co2 pistol right this second, and it does 410 fps....then again, it's .177

Velocity figures without projectile weight are meaningless, 410 fps for a 0.3 gram 0.177" BB is less than 2 ft/lbs of muzzle energy.

ok, so you think my gun :



Is worth building?

Also, would it be worth it to get a shock pump for this gun? I have a track pump that will go to 160 psi, but shockies go up to 300 psi, what should I use? (The chamber is 3" of 3/4" pvc or metal.

EDIT: I just realized that the value 3/4 is not read in the right way, it ends up unly being 6 ft/lbs, 242 fps with .75 in chamber

Are you good with fabrication and casting?

If so, I'd recommend you not get a shock pump. While shock pumps are very good, you'll eventually want high pressures in a larger chamber.

You could build a stirrup pump for less than a shock pump, and get similar pressures if you're heavy enough.

For a quick way of doing it, if you want 300 psi and can do 160 on a tracky, just take the I.D. of the track pump, halve it and there's your cylinder size.

With more pressure it could probably be worthwhile

ok, I might try my hand at a stirrup pump. I'm not sure how much pressure I can take it too, seeing as I weigh only 160 lbs, but that may be a fun and useful summer project. Anyone else?

maverik94 wrote:ok, I might try my hand at a stirrup pump. I'm not sure how much pressure I can take it too, seeing as I weigh only 160 lbs, but that may be a fun and useful summer project. Anyone else?

Depends. Seen as you've given us a weight measurement, if you just give us the max pressure you want to pump to and the cracking pressure of the check valve I'm sure someone could tell you an ideal I.D. for the chamber

In fact, it's very basic math

maverik94 wrote:ok, so you think my gun is worth building?

That's up to you, what are you using it for? If the power is sufficient and the size managable, why not.

@ inonickname, well seeing as the chamber is going to be all metal, Max pressures will be very high, However, I am not sure what the may pressure of the schrader valve and that of the blowgun valve will be. My guess for the schrader valve would be in the ballpark of 150 psi, and I believe the blowgun says it is rated to 120, so I am thinking I'm only going to go to about 120 psi.

@jackssmirkingrevenge well, I want a balance of portibility and power, however, portibility is more important. I want something that will, lets say, make small furry rodents regret eating the veggies inn the garden, and It would be nice if this gun could do some damge to a steel can, like the gun on the video you showed me. By the way, could you post the link to the topic about the gun? Thanks, you've really helped me a lot, anyone else?

EDIT: Do you think I should go with a 3/8" barrel at 7 ft/lbs and 261 fps, or a 5/16" barrel at 7.7 ft/lbs and 274 fps?

This shouldnt be the peoples gun, build it how YOU want it.

Well, I'm just asking what yall think. Also, I'm thinking of just having a few interchangeable chambers, like say a very small one that is portable abut not powerfull, a mediun portability and medium power chamber, and a high power/ lower portability chamber. Anyone else?

I say build it. There is now final way of telling how it will turn out until you make it. If you dont like it in the end, strip it of useful parts and try again. It wont cost you very much.

maverik94 wrote:@ inonickname, well seeing as the chamber is going to be all metal, Max pressures will be very high, However, I am not sure what the may pressure of the schrader valve and that of the blowgun valve will be. My guess for the schrader valve would be in the ballpark of 150 psi, and I believe the blowgun says it is rated to 120, so I am thinking I'm only going to go to about 120 psi.

@jackssmirkingrevenge well, I want a balance of portibility and power, however, portibility is more important. I want something that will, lets say, make small furry rodents regret eating the veggies inn the garden, and It would be nice if this gun could do some damge to a steel can, like the gun on the video you showed me. By the way, could you post the link to the topic about the gun? Thanks, you've really helped me a lot, anyone else?

EDIT: Do you think I should go with a 3/8" barrel at 7 ft/lbs and 261 fps, or a 5/16" barrel at 7.7 ft/lbs and 274 fps?

Please don't shoot at animals with this, it would take a lucky shot with such little power and accuracy isn't good considering it's a smoothbore.

The blowgun would handle more than that, just look at gipetto's piston cannon. Also the schrader will handle them much more, I routinely use them to 400 psi and tried a 1000 psi shock to one and they didn't fail. Gipetto tested one to 7000 psi and while the seal was cut, it didn't fail dramatically.

Gipetto tested one to 7000 psi and while the seal was cut, it didn't fail dramatically.

~10 000psi actually.(700bar)

Gippeto wrote:

Gipetto tested one to 7000 psi and while the seal was cut, it didn't fail dramatically.

~10 000psi actually.(700bar)

You should make a one pump cannon with that silly dead weight tester of yours gippeto.