300 PSI Pistol (FPS and damage pic)

[spade]

Hey this is my first post here but I've been looking around for a few months and figured I'd make an account when I had something to upload, sooooo......

Here's my first upload, not the first "spudgun" I've made, but I chose to upload this one because no one wants to see my completely n00b cannons, right? Ball valves...heh...

The pistol:
http://i1375.photobucket.com/albums/ag4 ... fbf454.jpg

This is my 300 psi pistol, with a blowgun as a trigger. It's not exactly the most hi-tech trigger, but the objective was to be simple, yet effective. It's full metal construction, using sch 40 galvanized pipe and fittings. Epoxy is used for attaching barrels to a piece of 1/8" pipe, so they can be interchanged by screwing them on and off of the front of the blowgun. I take it to 300 psi with my shock pump and it works quite well.

C:B ratio varies with barrels, but i like to stay within 2:1 to 4:1. The only barrel I've made so far is a piece of 12" 7/32 (about 0.20 in ID) brass tubing. That barrel would theoretically only give a C:B of 0.78:1, but it's much higher due to the fact that galvanized pipes are larger than the size they are listed as, making the tank volume larger than the calculated 0.29 cubic inches.

Damage pic (part of a screw through 5 cans): http://i1375.photobucket.com/albums/ag4 ... 6a6307.jpg

I did some chrony tests on two kinds of ammo:
4 grain .177 lead free pellet (widened skirt for 20 cal barrel) - 549 ft/sec @ 300 psi
~7 grain 5mm ball bearing - 480 ft/sec @ 300 psi

[jackssmirkingrevenge]

Simple, yet effective.

You said it, very nice! That blowgun should be OK up to 400 psi at least.

[Talk]

blowgun12.JPG (8.73 KiB) Viewed 2684 times

if this is your blowgun you can make a trigger system like this

blowgun13.JPG (32.73 KiB) Viewed 2684 times

and then put the blowgun into another body of a gun, i used a FamasG2 in the pic but it can be a pistol or any rifle you want

i can't accomplish my dream of making a M82A2 design pneumatic gun because i cant make the M82A2 body but i think a body of FamasG2 can be made out of wood to put your blowgun inside making your pneumatic look realistic

[spade]

You said it, very nice! That blowgun should be OK up to 400 psi at least.

Thank you sir I have taken it to what looks like about 350 on my shock pump gauge (gauge goes to 300), but it looks like I'll have to try 400...if that's safe for the pump? Here's the pump I have, if that helps:

Talk that is an interesting idea, however I was thinking for some of my other pneumatics I was maybe going to make wooden grips/stocks for them, as I don't have any airsoft gun bodies I'm able to use right now, but I have lots of planks taking up space.

[jackssmirkingrevenge]

Thank you sir I have taken it to what looks like about 350 on my shock pump gauge (gauge goes to 300), but it looks like I'll have to try 400...if that's safe for the pump?

Safe for the pump, though not safe for the gauge, if you take it to 400 it will likely not return to zero.

In my experience the blowgun can take around 500 psi safely without leaking, though it does become progressively harder to open, so Talk's idea for a trigger is one that would make sense.

[spade]

I see... thanks for the information. 8)