In Sci Fi, the majority of weapons come in the form of either some kind of energy beam/bolt, or as testosterone-dripping slug-throwers. In Mass Effect and the Aldreaverse utilize weapons that fire small metal shavings that are much, much smaller than today's fire arms.
These projectiles are often depicted creating an ionized trail in their path due to the sheer speeds they travel at (ranging from supersonic, hypersonic, or even flat out a percentage of c).
For now we'll ignore how they are fired (advanced magneto gravitic space magic tech or whatever else the universe uses), and the question of the projectile's actually doing anything to the target instead of sailing right through will be explored in another post.
For now, all I'm asking is such a projectile be feasible in atmosphere?
Some characteristics:
The projectile is a sub gram metallic projectile
The projectile travels at extreme velocities
The projectile is so fast, it leaves behind a ionized corona that is visible to the naked eye