Just pondering here, has there ever been anyone that has tested a liquid/gel propellant in a rifle shell, rather than powder? Neglecting the issues of leakage at this point, I'm just curious if this was ever tried and if so, what kind of results they found.

Hey, with a 50 mile commute to work each day, what else am I supposed to think about while sitting in traffic? Never mind, don't answer that...

Jethro,
do a serach on "bi-metal" bullets... they've used liquid fuel...

there are advantages for liquids... but tons of hassle, as can be imagined...

modren powders "run out of steam" with a burn rate i 7500 FPS, IIRC, and this is the UPPER limit of conventional bullets. Generally the "Fastest" a bullet can go, regardless of ammount, over capacity, barrel length, etc, would be 80% of the burn rate, in the most efficent barrel possible. 80% is NOT an exact number, but it's more or less the mean.

So, if you had a 50 bmg necked down to 22, you would top out about 6000 fps... this has been proven....

The REASON that pwoders have retarded burns is to control the speed. This is also a function of surface area and surface coatings. This is what fg burns slower than ffg, than fffg (for example) as fg is FAR larger in surface area, but IN THEORY exactly the same composision. When surface area is the same (winchester ball powders) they change both the internal compossition and the surface coating, to controll the burn rate...

Why control the burn rate... ah, this is CRITICAL... a "slower" burn rate means that if you lined the powder up in a line for several feet, and lit it, it would take MORE time to transfer energy to the next particle AND to convert solids to gases... since gases are what actually pushes the bullet, you control PRESSURE (and volume, which is ACTUALLY the critical item, but not for this level)

Liquids, on the other can, can be diluted, concentrated, and controlled on a much smaller scale... they also can have a faster burn rate, with controllable pressure, and/or a controled gas expansion... due to several factors, the first being that a liquid is in a higher energy state than a solid, of the same material... think ice, water, steam,,,, and you want to make STEAM..

Theh down sides are we haven't figured out how to handle liquids in bullets yet... and no one has found a REASON for them in SHOULDER fired weapons... we can already take just about any caliber, add enough case and powder, and it becomes unshootable for your average shooter... a 270 on a RUM case, in a 7# rifle would just whip even me...

So, it's a niche product, better suited for HUGE cases (where it is used today) like artillery and 20, 30, mm phalanx guns...

jeffe

There's a lot of military research going on on liquid propellants for guns. The information's not in the public domain, but if you use the right keywords on the search engines you can find bits and pieces. Nothing we're going to be using in the near future, though.

Liquid propellants schmellandts. Lets get serious about rail guns. You know, electromagnetic propulsion. I've seen some military tests achieving 10,000 fps. Some of you electronic gurus ought to be able to design a battery pack that would be portable enough to make a shoulder fired rail gun practical.