compression ignition bp rifle ???

[burnt_servo]

was looking at some piston fire starters ( http://www.youtube.com/watch?v=oiMkgC55RGg for those not familar ) .

and it struck me that this should be possible to be adapted to a black powder rifle .

a bit of black powder on the tip of the piston , the other end of the piston is the trigger mechanisim , and some sort of lock that prevents the piston from coming all the way back out when the bp is ignited . the whole things is powered by a coil spring .

anyways the trigger is pulled , the bp is compressed and ignited pushing back the piston 3 or 4 inches revealing a small touch hole which ignites the main charge .

open the lock , pull the piston out , swap in a freshly charged one and your priming system is good to go again .

 

[Skinny 1950]

The main problem is the fouling that BP causes. In order to produce the temperatures required to ignite BP you need a compression ratio of at least 14:1 which requires very tight tolerances between the piston and the cylinder,even more so with small diameters.

 

[The Frogge]

The Daisy caseless .22 used compressed air to ignite. The air from a piston went through a small hole and this created enough heat to light the propellant. Something similar could probably be done with some of the bp pellets.

 

[burnt_servo]

i never thought of super heating the air and pushing it through the touchhole , that would get rid of most of the black powder fouling problem and make it so a person wouldn't have to charge the end of the tube with a small charge of bp .....

now to see if google coughs up with some picstures of the daisy rifle

 

[Skinny 1950]

Maybe some kind of one way check valve on the injector or the pressure will blow the piston back and foul up the cylinder.

 

[contaucreek]

I collect antique diesel engines and find this a fascinating concept. I bet it can be done !

 

[Skinny 1950]

I have a couple of steam engines..one of those small german double acting modern ones and an antique 1 1/4 inch bore.
Lets face it... the engine as we know it evolved from firearms.
A very early design ran on gunpowder...backfires were a big problem not to mention fouling.

 

[contaucreek]

U.S. Patent 2947221 1959 Olin Corporation. Patented a firearm using compression ignition of a LIQUID propellant.