First of all, gunpowder is what was used before the advent of smokeless propellants. What we call gun powder today is actually a solid granular
propellant made of nitrocellulose - which is why it was first called "Gun cotton".
A buddy of mine was a mix-technician at United Technlogies rocket division. He mixed the materials to make solid fuel rockets and poured it into the moulds. Various compounds and mixtures are amazingly powerful. Different mixes have different burn rates, just like smokeless powders.
But the engineers, physicts and chemists who create this stuff told him that nothing will burn "cleanly" if you want to control the burn rate.
As to new technologies... Remington tried with their electronic ignition system. That's fine on a sports rifle, target gun or match gun. Not so fine when it's used to defend against any kind of predator. I've never trusted batteries to work just when I need them. I'm not staking my life on the battery.
Several handgun designs show that we can lower the bore axis even more to reduce recoil. See the S&W M61 Escort and 422 series of .22's or the Mateba revolver. The concept of a magazine-fed self-loader means a compact gun with the bore higher than the hand or dictates a magazine located outside of the handgrip (e.g. the 1896 Mauser).
I can think of at least two examples of innovations that did not work. Anyone who has seen or fired a 13mm
Gyro-Jet Rocket Pistol may recall it was designed in the early 60's.
The other gun was the bizzare Dardick Revolver which fired a "
tround".
Dardick 1500 Revolver
These guns worked, but not always 100% due to ammo issues. But no one would fund their next steps. People are out there thinking of new ways to project power to remote locations. Just so far, the use of smokeless powder and led bullet seems to be the most efficient.
