i want to make a .177 full auto airgun

[beastmode986]

Should i use a regulator?

Also I'm going to shoot.25 pellets what size metal tubing fits it and where can I buy it?

[beastmode986]

would this pilot and qev work?
im going to shoot .22 pellets maybe .25 what size brakeline will fit .22s
also will a 1/2 in qev be to big?

[qwerty]

A regulator would be needed as a QEV can't withstand un-regulated CO2 and a 1/2 QEV would be fine but 1/4 would be more practical for what you need.

[beastmode986]

ok thanks i will make a 1/4 in qev
whats the cheapest re4gulator i can get that will suit my needs?
what should i use as a ppilot? should i just do what wyz did?

[beastmode986]

i also have a hammervalve from a tippman 98 custom. should i just use that?

[Gun Freak]

It's gonna be really annoying having to refill a co2 tank every 20 shots...

[beastmode986]

thats true but i dont think i have any other options that will yield the same performance

[beastmode986]

would it be possible for me to swap the valve on the co2 tank with a 3000 psi hpa reg and only fill it to 1000 psi?

[Gun Freak]

You really don't wanna do that. At least not for 20 shots. Let's think of a way to get more shots out of that 20oz tank. Since this is small caliber, we can come up with a system that will waste less or no air (which eliminates the QEV/slide valve option). A hammer valve would work. You can run the remote line to a smaller tank on the gun which would be connected to the hammer valve (you can probably use the one you have, can we see pictures of it?), and then your breech load leading to a nice barrel, as close to the diameter of your ammo as possible.

[beastmode986]

ok sounds good ill take pics now also i have two hammer valves and are you suggesting a air chamber on the gunto a ball valve or something connected to a fitting the quick connect hooks onto and fill that way? since im shooting .22s most likely but possibly .25s i want a good velocity say 750+ fps? would i be able to acheive that at 150 psi a shot? i want to make it look similar to a barret m107 50 cal or something cool ive had a few ideas just not sure how id make a body yet

[beastmode986]

hammer valves




heres the oxygen tank i have


the tippman hammer valve has blowback:( so i need to modify it if its used butt it also is already threaded for the quick connect fitting for the co2 tank and can handle the pressure without a reg(tippman didnt have a reg on it that i got it from)

[Gun Freak]

Do you have a co2 tank? Is that tank a modified fire extinguisher? You're not helping me out here much

Those valves look alright but I'm not sure how you'll use them...

About pressure, you need a lot to use a hammer valve and get a high velocity like 750 fps, especially with a 22 or 25. I recommend 22 cal because you can buy a perfect barrel, albeit smoothbore, at the hardware store. 1/4" OD K&S brass has an ID of .222".

[beastmode986]

ok ill shoot .22 the air tank pictured is a modified oxygen tank. yes i do have a 20 oz co2 tank it just wasnt pictured

[Gun Freak]

Ok. What's the rating on the oxy tank? It looks like one of those relatively low pressure ones like propane tanks but if I'm mistaken, you could possible fill it with a fridgy and use it for your air source... Just a thought. I need to pressure test one of those propane tanks

[beastmode986]

more info on the hammer valves

smaller valve-took from a crossman pump master
-pumpmaster shot a 600+fps
-i drilled out the exhaust hole a little bigger
-sturdy construction
-air tight
thats basically all i have to say oh yeah also i can put a weaker or stronger spring in it
bigger valve
came from a tippman 98 custom
can run unregged co2 no problem
has a housing/sleeve i can get you a picture of
-housing will most likely ease construction