On Mon, 24 Apr 2006 01:47:41 -0500, Don Foreman
wrote:

On Sun, 23 Apr 2006 21:33:24 GMT, Gunner
wrote:

On 23 Apr 2006 09:08:19 -0700, wrote:

Gunner,

Why not try something exotic such as an electrically fired gun?

The propellant is a couple of drops of plain, old, water, through wich
a heavy electric current is discharged from a capacitor.

What do you think?

Sounds interesting..and complicated. Im not much of an electronics
tech to be frank. Board changer is more my skill level. Getting down
to component level and I start to flounder. And I suspect that the
power supply and caps bank needed to do instant electrolysis might be
a bit heavy.

I suspect that this isn't electrolysis but simply instant
high-pressure hot steam produced by heat from a spark/arc.

It's an interesting idea.

A fairly powerful production air rifle has energy of about 30 joules
(22 ft lb), as a .177 with 1100 fps muzzle velocity. This would not
require a large capacitor. One available 48 joule 450-volt
photoflash cap is 1-3/4" dia x 2-1/2" long. It could be charged in
a few seconds with 4 AA cells and suitable circuitry. Four alkaline
AA cells contain a total of about 29,000 joules, i.e. many shots!

However, for perspective, a .22 rimfire short is about 157 joules.
I don't know what energy the Lewis & Clark or Austrian infantry
rifles had. However, musing on....

The original .45 ACP round in a long barrel (SMG) is about 520
joules. http://www.sightm1911.com/Care/45acp.htm . Taking it
to that level, there is a 2000 volt 500uF 1000 joule capacitor that
is 2" dia x 4-1/8" long, and you'd get at least 25 shots out of 4 AA
cells (for 2 bux) even with fairly lousy efficiency in the
circuitry. That's twice the energy of the .45 ACP but still only
half the energy of a .30-30 or 7.62mm Kurz (short). Still, not bad
for an "air" rifle with no flash and no supersonic "crack". Subsonic
bang is more difficult to auditorily localize because it contains
less high frequency content. Phase resolution is therefore less with
the fixed distance beween ears.

What about pressure build time and attainable muzzle velocity? I
can attest that a 50 joule photoflash cap will vaporize the end of a
screwdriver with a report that sounds a lot more like the crack of a
rifle than the bang of a pistol, which infers that it can dump its
load rather quickly producing a hypersonic shockwave.

Vaporizing water with a shot of energy would produce much more volume
of expanding high-pressure gas to accelerate a projectile continuously
thru the length of a barrel. However, an "air" rifle can not
attain sonic velocity unless the "air" is quite hot, so higher
energy infers large-caliber low-velocity bullets, most effective at
ranges under 100 meters and probably best at less than 50 meters.

It's an interesting idea. There'd be a few details to work out.....


You figure the circuitry out..Ill build the Steamgun. Stainless steel
of course. The water injection/volume control sounds a bit interesting
to figure out..but if a steam engine can do it...

Gunner

"I think this is because of your belief in biological Marxism.
As a genetic communist you feel that noticing behavioural
patterns relating to race would cause a conflict with your belief
in biological Marxism." Big Pete, famous Usenet Racist