It appears there is nothing inherently wrong with the concept, other than inadequate initial projectile velocity: a round can actually be stopped if a finger or even piece of cardboard is held directly at the end of the barrel, and will burn its fuel uselessly.
It appears. There is nothing inherently wrong with the concept. The concept is other than inadequate initial projectile velocity. A round can actually be stopped. A finger is held directly at the end of the barrel. Even piece of cardboard is held directly at the end of the barrel. A finger will burn its fuel uselessly. Even piece of cardboard will burn its fuel uselessly.