SpudFiles

Over Christmas break, I plan on starting a new project, so here it is. I want to build a compact, full metal handgun. Specs are:
4.5mm (.177 cal.)x4-5" barrel
1/4 or 3/8" chamber(not sure of length)
Anyway, I want the gun to be no longer than 7" long. The gun will be a single shot gun. I am not sure what kind of valve I am going to use. Makbe a piston valve, but I am kind-of thinking of a hammer/pushbutton valve. Anyway, I hope this will be a fun little project. What I want from you is some input. What kind of vlave do you think I should use? I'd prefer not to go with a coaxial piston valve, but I can if I need to. Also, do y'all have any other suggestions for this gun? By the way, I am thinking of a breakbarrel breechloading design, so any ideas or alternatives on that? Thanks! And I will report on any progress here.

sound like a good project i will be following this 1.
i think mebey a push buton valve?

sonds good, i say piston valve with pushbutton pilot.

im going to do a winter project and its the one in my sig

sonds good, i say piston valve with pushbutton pilot.

The only problem with that is that having a pushbutton valve and a piston valve would take up a lot of space. I am kindof leaning toward a hammer or pushbutton valve to tell the truth.

a piston valve and push button doesnt have to take up much space at all, my old brass coax was a good example

well, not much space in a rifle, but in a small handgun you need to conserva as much space as possible, so I think I'll go with a pushbutton/hammer valve.

If you want compactness and power for single shots I think a coaxial is your best bet, why not combine something like this with your hammer system?

you could buy a manually actuated 3 way spool or poppet valve... probably even 1/8" valves may offer good flow for 4.5mm cal

but in order to get good opening time you would need to get either:
a piloted valve (so one which has an inbuilt miniature valve which 'pilots' the spool)

or

a poppet valve (I don't know if this is true of all of them... but the two poppet valves that I bought switch instantly - probably because they are not balanced and once they open air pressure helps them to open even faster)

the whole gun would consist of the 3 way valve itself (which would act as the main valve) a short length of pipe to act as the chamber and the barrel

you could even put a small air cylinder and use the same loading mech as I used on my semi

I suggest coaxial QDV. It will give you the best performance in the most compact package.

I am working on a piston valve, piloted by a blow gun.... the gun is just under a 18 in but it has a 12 in barrel... the total length minus the barrel is that of a 1/4'' T and a 1/4" elbow with a 1/4'' close nipple in between.

Just took it upto 250psi. louder than your mother after the dog pees on the floor.

Like mine? i just used 15mm copper coaxail and i get very nice results with an O-ringed piston at 200psi i get 500fps +. But this is very old(3 months) and i didn't bother posting it. Overall it's very fun, loud! and easy to service. ( i can hand open and close everything because i just use o rings.)

looking at your avatar, why not try and base it off a flint-lock pistol. Nothen sexier than a flint-lock blunderbuss... coincidentally there is also nothing as “badass” as one

A sawed-off double barrel is slightly more badass..

why hasn't anybody made a double barrel coax yet....????

why hasn't anybody made a double barrel coax yet....????

we are waiting for you to set the bar... you seem pretty good at the handheld shotgun thing.

I'll say the oring idea is pretty good. I'll have to try it out some day, but the idea of a flintlock pistol is awsome as well. It would be a pain in the butt to make though.

Brian the brain wrote:why hasn't anybody made a double barrel coax yet....????

Not a coax but surely 9 barrels is enough