If you're trying to build weapons they are, yes. But we're not trying to build weapons here, are we?ETGs are impractical after a certain point.
Which is more than can be done with "conventional" solid propellant guns, which have already essentially reached their limits, and have been studied to death over the last hundred years. In fact, I'd argue that for the kind of launchers we typically build, which are large and obnoxiously loud, CLGGs can reach higher performance than solid propellant guns, and with less illegal compounds laying around one's property.Currently you can only really increase pressure or size in spudguns, it can't go that much further.
What many of you don't seem to realize is that what is already permitted for discussion here is the future. The ideas we can currently discuss here - railguns, ETGs, *certain esoteric hydrogen producing reactions*, induction launchers, CLGGs - these hold greater potential than modern solid propellants for serious projectile launching. I'm not implying that we'll have EM handguns as ubiquitous weapons any time soon, but the big stuff is leaning progressively further away from conventional means and the fast stuff hasn't had much use for them since the forties.
Should we be able to discuss solid propellants here, in some limited and hidden fashion as SB15 suggested? Yes, and we already do. It's called the private messaging system. If PCGUY wanted to create a proper section for it, that'd be great, but the six or seven of us aren't exactly barred from communication with each other as it is.
Directions for the site? We need a change in attitude. We have people claiming that gas gun tech "can't go much further", when, to my knowledge, no one has even used helium as a buffer gas in a hybrid mix, or hydrogen or methane as a fuel. Can't go much further? Not unless that means we've finally managed to reach 5% of the performance we stand to achieve. We've barely even started. Laziness and ignorance is not equivalent to the exhaustion of our subject matter. Three years ago, Larda built a launcher with an energy density on the same order of magnitude as that of a firearm, using only air and propane as a propellant. How can anyone dismiss this as a toy technology, when even the most primitive propellants we use can achieve such performance? Solid explosives are wonderfully useful tools, but we need to develop some appreciation for the impressive technologies we already have, and are too lazy to put to use.