Page 1 of 2

500psi Bolt Action Rifle

Posted: Tue Oct 06, 2009 9:26 pm
by Killjoy
Hey there fellas! First I want to say sorry for being MIA this past year. College, girlfriend, and making money took up a lot more time then I expected, which is why I've been roaming the site but never posting.
Despite being distracted, I've still built several cannons (including my 20x hybrid rifle) which should slowly be rolling onto the site over the next couple weeks. Now onto what ya'll care about.

500psi Bolt Action Rifle

Specifications:
Chamber: 6" long 1/2" sch 40 steel pipe. End welded shut.
Barrel: 3/4" sch80 PVC pipe. 33" Long.
Valve: 1/2" QEV piloted by a slide check valve.
Bolt Action: 12g CO2 cartridge with ends cut off and nut welded to the inside so handle can be screwed in. Barrel reinforced by 1" type m copper pipe.
Ammo:8g C02 cartridge cut in half and the nose filled with about 1oz of lead.

Features:
Trigger operated slide check valve-Fast reload
Built on a composite rifle stock for a SKS rifle.
Pressure Chamber hidden in grip.


Obviously it's far from finished, I ran out of time and had to leave it and go to college. But I have plans for when I get back.

Future Plans:
-Find a proper return spring for the sliding check valve.
-Seal the bolt handle into the bolt with epoxy. Right now there is a gap and it lets out a lot of air.
-Glue barrel into copper pipe. Right now it is just held in by friction because I wanted to be able to disassemble it to fix things.
-Bondo all major gaps and sand smooth. Finish with either matte black or desert camo as a paint job.
-Add weaver mount for scope.

Rifle:


Image

Image

Image

Image

Trigger Mechanism:
I soldered two pieces of copper together to give something for the trigger end to push against and slide the valve body forward.
The trigger is a piece of 1/4" mild steel rod I ground down and bent. I used coat hanger wire as a retaining pin.

Image

Pilot valve closed and filling chamber:
Image

Pilot valve slid forward. QEV has been piloted and filling connection is closed:
Image

Videos:

[youtube][/youtube]

[youtube][/youtube]

Posted: Tue Oct 06, 2009 9:33 pm
by rp181
Very nice. Where do you get QEV's for that high pressure?

Posted: Tue Oct 06, 2009 9:42 pm
by Killjoy
Found a pair on Ebay. Ratings were in the 300psi range but they handle 500psi just fine.

Posted: Tue Oct 06, 2009 9:50 pm
by c11man
very nice gun, what do you pressureize it with?

and most qevs can handle at least 500psi

Posted: Tue Oct 06, 2009 9:56 pm
by Crna Legija
Nice gun love the stock. I cant find QEVS on ebay there all paint ball ones.

I don't really get how it works, is it like this:
http://www.spudfiles.com/forums/semi-auto-t160.html

Posted: Tue Oct 06, 2009 10:00 pm
by Killjoy
I use a fridge compressor I picked up at college. I've been surprised at what a workhorse it is.
And the pilot mechanism is very similar to Clide's, I just used a slide check valve I found on ebay and rigged up a trigger to move the slider.

Posted: Tue Oct 06, 2009 10:05 pm
by jackssmirkingrevenge
Good stuff, and surprisingly quiet too at those pressures, probably due to the C:B ratio.

Also, glad someone's using my old slug suggestion :D

Posted: Tue Oct 06, 2009 10:56 pm
by absinthe
did the slug go trough the bin at 400 psi? my copper would atleast dent the you know what outta it at that range

Posted: Wed Oct 07, 2009 12:48 am
by rikukiakuchiki777
Very nice gun! I know you said you have it planned, but the scope would just finish this project perfectly. Can't wait to see this finished :D

Posted: Wed Oct 07, 2009 1:42 am
by qwerty
Lovely gun very clean i agree with rikukiakuchiki777 a scope or red dot would finish it quite nicely.

Posted: Wed Oct 07, 2009 2:11 am
by Moonbogg
Great gun and presentation. In your last video I couldn't help but think, "dude lookout for the fire extinguisher!"

Posted: Wed Oct 07, 2009 2:33 am
by POLAND_SPUD
wow it looks so neat... just like a real rifle...
I've been surprised at what a workhorse it is.
I told ya... :)

Posted: Wed Oct 07, 2009 5:05 am
by psycix
Good job. It looks neat and the performance should be good too. I like how you are using a slide-check, more people should do that.

How about a trigger guard?

Posted: Wed Oct 07, 2009 5:34 am
by john bunsenburner
Reading through jsr's idea about the slug and the thread about ferrocrete try this:

get the empty CO<sub>2</sub> canister half and fill the nose with a mixture of lead shot used for diving or to refill shotgun shells, it is fairly cheep and cement, let it cure and you should have a really nice projectile, alternatively just use lead like in jsr's original idea. House the whole thing in the plastic "tubing" of a shell and done!

Posted: Wed Oct 07, 2009 9:50 am
by IlovePsi
u need a bigger chamber and a metal barrel , but nice gun i like it , awesome trigger