I'm curious to know why I haven't been able to find any information on this. I can't be the only person to have thought of it, as a matter of a fact it was literally my first thought when a friend of mine showed me his new air rifle and all the random crap he can shoot with it.
I'm a hard science and engineering guy but I'm also fairly well informed in the legal arena (at least as well informed as you can be with US law and 6 million pages of code that change every quarter)
The federal definition of a "firearm" is essentially anything that uses a cartridge or can be readily converted to fire a slug from a cartridge. The definition of a "weapon" is a tool intended to maim or kill. Hence a muzzle loader, or other "gun" can be considered a weapon but is not considered a firearm as the slug and load are separate.
Obviously laws vary immensely by state but based on that loose information and the fact that there are production air rifles obtaining close to cartridge level muzzle energy. I believe I saw one manufacturer claim a muzzle energy of around 500 ft/lbs or almost 700 joules. Which for compressed air alone is Impressive.
A .308 cartridge has a muzzle energy of a much more powerful 3500 joules or more owing to the massive pressure that can build up from nitro explosive detonation. This massive internal pressure is how solid fuel missiles can obtain such high velocities.
At the end of the day both an airgun and cartridge round work under the same principle, a gas is expanded through a nozzle causing an acceleration of the slug in the opposite vector.
The difference is the pressure ratio. 100 grams of gas expanding through a nozzle at 200 bar vs 1500 bar or more is going to going to achieve a higher velocity. Higher pressure requires that more energy in the form of heat be added to the system. More heat energy, more expansion, higher compression ratio, faster slug.
So... why not use electricity, or some other form of conductive heating to exponentially increase power with a minimal increase in complexity and would still not have to be treated as a firearm given that there is no combustion of gas or solid material.
Instead of:
Compressed gas > regulator valve > nozzle
You would have compressed gas > regulator valve > heating chamber > nozzle
An electric current run through some sort of mesh would be reasonably efficient at adding heat, but there would obviously be some inefficiencies within the chamber and nozzle. Compressed gas leaving a tank is only at ambient temperature or very close depending on how recently it was filled, increasing the gas temperature from say 20 degrees C to 200 degrees C would be easily obtainable and increase power 10 times minus all our favorite variables like friction, nozzle choke, non laminar flow etc
There seems to be alot of competition for powerful air guns.
I'm a hard science and engineering guy but I'm also fairly well informed in the legal arena (at least as well informed as you can be with US law and 6 million pages of code that change every quarter)
The federal definition of a "firearm" is essentially anything that uses a cartridge or can be readily converted to fire a slug from a cartridge. The definition of a "weapon" is a tool intended to maim or kill. Hence a muzzle loader, or other "gun" can be considered a weapon but is not considered a firearm as the slug and load are separate.
Obviously laws vary immensely by state but based on that loose information and the fact that there are production air rifles obtaining close to cartridge level muzzle energy. I believe I saw one manufacturer claim a muzzle energy of around 500 ft/lbs or almost 700 joules. Which for compressed air alone is Impressive.
A .308 cartridge has a muzzle energy of a much more powerful 3500 joules or more owing to the massive pressure that can build up from nitro explosive detonation. This massive internal pressure is how solid fuel missiles can obtain such high velocities.
At the end of the day both an airgun and cartridge round work under the same principle, a gas is expanded through a nozzle causing an acceleration of the slug in the opposite vector.
The difference is the pressure ratio. 100 grams of gas expanding through a nozzle at 200 bar vs 1500 bar or more is going to going to achieve a higher velocity. Higher pressure requires that more energy in the form of heat be added to the system. More heat energy, more expansion, higher compression ratio, faster slug.
So... why not use electricity, or some other form of conductive heating to exponentially increase power with a minimal increase in complexity and would still not have to be treated as a firearm given that there is no combustion of gas or solid material.
Instead of:
Compressed gas > regulator valve > nozzle
You would have compressed gas > regulator valve > heating chamber > nozzle
An electric current run through some sort of mesh would be reasonably efficient at adding heat, but there would obviously be some inefficiencies within the chamber and nozzle. Compressed gas leaving a tank is only at ambient temperature or very close depending on how recently it was filled, increasing the gas temperature from say 20 degrees C to 200 degrees C would be easily obtainable and increase power 10 times minus all our favorite variables like friction, nozzle choke, non laminar flow etc
There seems to be alot of competition for powerful air guns.
