Comments on: Latest in Firearms—a Rifle That Shoots With Liquid Gas

By: cbellamy

cbellamy — Wed, 03 Sep 2008 20:03:24 +0000

CO2 in those large 50 pound cylinders is in a liquid form. If the pressure is suddenly released, the CO2 cools quickly, and condenses into dry ice flakes. The gun would have probably produced little dry ice pellets as it was fired. Here is a device that makes blocks of dry ice by that principle. I've used one before (back when I was a chemist), and all it takes is about 30 seconds to make a 1-pound block of dry ice with this device. All it really is is a box with porous sides to catch the CO2 "snow" and hold it as it packs into a block.

By: fluffy

fluffy — Tue, 02 Sep 2008 21:30:39 +0000

CO2 does liquify at a high enough pressure and low enough temperature. All gases do, really. But probably not at the pressures/temperatures that toy was dealing with.

Fun fact: liquid CO2 is pretty good at dissolving caffeine. The way they decaffeinate coffee is by bathing the beans in liquid CO2, which draws most of it out. The extracted caffeine is then used in soda, caffeine pills, etc.

By: Toronto

Toronto — Tue, 02 Sep 2008 21:13:59 +0000

Well, “LPG” stands for “Liquified Petrolium Gas” (a mix of propane and butane.) But this article mentions “Carbonic gas” which is also known as carbon dioxide. And CO2 doesn’t liquify, does it?

I can see why the little 8, 12 and 16gm CO2 cartridges became more popular for pistols. A 40,000 round supply of gas would probably be the size of a 20lb propane tank.

By: fluffy

fluffy — Tue, 02 Sep 2008 20:06:37 +0000

Although I get what they’re saying, isn’t “liquid gas” sort of a contradiction in terms?

Also, how could it be recoil-free? It might be very low-recoil but there’ll still be some. Newton’s third law etc.

I may be entirely too pedantic.