Diesel air rifle

[blind ear]

Do rules of production forbid building an air rifle that takes advantage of diesel ignition? Does anyone know the potential for diesel propulsion/velocity? In a large bore, 30 cal or greater is seems it might offer big advantages in hunting. A smaller air charge could be used to ignite the propellant to higher velosities. Just wondered if the subject had been broached? I went through the search a little but didn't find anything. eddiegjr

[dave]

Do some research on the Daisy VL and the Weihrauch EL54 Barrakuda. The Daisy used caseless ammo with a propellant charge. It was ruled a firearm and removed from production. The Barrakuda was an HW35 with ether injection. It made almost uncontrollable power, not real consistant or accurate.

[torpedoman]

have been tinkering with the idea of making a propane powered rifle. electric ignition

[Victor3]

 IIRC, there was at least one recently made model by Mendoza designed to rely on oil deliberately injected into the air chamber to increase its velocity via the diesel effect.

 Most medium/high-power spring guns will exibit dieseling evidenced by smoke and higher velocity when new (or newly re-lubed) until excess lube has burned off. After that, velocity generally drops.

 Some believe that all of the higher-powered spring guns gain a good percentage of their velocity from the burning of residual oil. I don't buy that theory though.

 I don't believe that a practical 30+ cal rifled barrel spring gun could be made. The spring would have to be very powerful to get reasonable velocity (diesel or not), and the gun very large and heavily built. I doubt one would want to cock, carry or shoot such a rifle.

[blind ear]

I was thinking pump up gun. The pressure chamber would be designed to hold enough air volume to detonate a given delivered volume of oil. The pressure chamber could become part of the ignition chamber when the trigger was fired. A smaller air tank but heavier with tough valves. The pump ups I had as a kid in the 50s & 60s would "crack" when fired with oil but wouldn't last long.

The crossman that I had, I shot it so much that I didn't use the back site. IF someone borrowed it they would have to straighten the site up and zero the gun. They didn't ask but once. I still shoot an air gun almost daily but it isn't as accurate or well built as my old crossman. My eyes arn't the ones I once had either.

Just day dreamin, eddie

[dave]

Propane powered guns are nothing new, they have been used for paintball for a while now.
The Mendoza guns don't have oil injection or anything of the sort. There is a felt oil reservoir on the piston behind the seal, and an oil port on the breech to add oil. The felt ring wipes the cylinder wall and deposits oil on it, and that oil gets into the compression chamber, causing detonation.
Multipump air rifles don't detonate or diesel. Deiseling is caused by the rapid compression of air in front of the piston. Rapid compression causes the air to get hot, something around 1700*F, which in turn ignites any oil in the chamber. Pump rifles don't generate that kind of pressure, and the pressure is built slowly, so not a lot of heat is generated. When the gun is fired and the pressure is released, the air is cooled rapidly, so theres no way it can ignite anything.

[blind ear]

If you put a drop of oil dirrectly behind the pellet after it was pushed into the barrel you could get detonation, at least it sounded like it and shot like it. eddie