I agree Uplinker, for the most part. It is just that the thing looks too simple, as you note about looking like a fancy rocket that uses air for the oxidizer.
Secondly, detonation is not simply fast burning, best unnerstan, ... the substance just completely comes apart at the molecular level of the compound. Hence the shockwave more a factor than extremely fast burning of gunpowder-type compounds. The sharp crack from your rifle is truly a shock wave, but not from the propellant, rather the projectile being supersonic.
Something about this sounds really too good to be true. And BTW, you can get the ramjet motor working at lots less mach than folks assume. See the SAM missile we used back in the sixties - Bomarc, and I tink the French had a mach 3+ missile about that time, as well.
Last edited by gums; 15th May 2021 at 15:23.
Reason: added stuf