Combustion sniper?

[Strake]

hello all.
for some time ive been thinking of building a pneumatic sniper rifle but it would take to long to refuel and would have less power than a combustion sniper which would take a lot less time setting up for the next shot. i would be planning on shooting marbles.

to my questions if i was to build one outta metal what would be the chance of it going F*&king bang in my face?

and i would i need a larger chamber for better air to fuel ratios?

[Carlman]

a pneumatic would have more power than a combustion per given parameters.

there is all types of metal around to make one out of, not really any chance of it going F*&king bang in your face unless you made it out of aluminum foil.

It would be easier to get the right mix if its a 'spray and pray' if he chamber was larger.

[bluerussetboy]

It looks like you need to do plenty more research. Like carlman has already said pneumatics are more powerful than combustions. Large advanced combustions are temperamental, smaller metal combustions are down right finicky pains in the @sses. It is mostly getting the consistent fuel mixture. This isn't so hard if you use a metering system.
Smaller pneumatics are more versatile and powerful. For example, a small barrel sealer with a 6 cu in. chamber with a 60" X 1/2" barrel with a 2.5 gram projectile(baby carrot) pumped up to 150 psi should give you somewhere 600-700 fps. Fill that same launcher to 300 psi and you'll get ~900 fps. Fairly powerful for such a small launcher. Pumping the small chamber up to 150 psi with a bike pump only takes about 8 strokes. Not much time at all.

[SpudFarm]

not much work with the eight strokes eighter..

[DYI]

I don't think that a small metal combustion would be too difficult to get working, provided you do an accurate liquid volume measurement of the meter and chamber.

It brings to mind the question though, is it really worth it? It will be too weak even for plinking. For a launcher as small as you want, you either need a high pressure pneumatic or a hybrid for decent power.

[Strake]

thanks for the responses,
i never new that pneumatics where more powerful than combustions. i've always really like pneumatics but i was led to believe that they are a pain in the rear having to refill them every time. thats why i wanted to build a small combustible. ive got a pneumatic rifle at home (not posted) that gets to about 100-130psi, i shoot a projectile and it wont go barley any. i suppose if i had better ammo it would be not to bad i was using 13 cm darts they worked alright then i was using nails that i made fit snuggly into the barrel and they would shoot probably 10 meters tops. this pneumatic was a pain to fill up also because the chamber was a reasonable size, (small fire extinguisher).

[hyldgaard]

You could make yourself a refilling tank, then refilling of a pneumatic would be even quicker than refueling a combustion. Ofcourse you would have to spend some time pumping before actually being able to shoot, but reload times would be lower. As an alternative to pumping you could get yourself a fridge compressor to do the work for you.
Gippeto got some co2 fire extinguishers for free to use as storage tanks, just to give you an idea http://www.spudfiles.com/forums/high-pr ... 14027.html
Casper.