I was imagining air behaving like water. If you send first projectile it'll slow down but move some water to the sides. Second will slow down less so it'll catch up with the first one but it will also push some water to the sides. Third also will catch up with the previous ones but each subsequent one will get farther as it travels through space punched out by previous ones.
I don't think it's practical in any manner but I think such brute-forcing stream of projectiles out of atmosphere by literally punching hole in it might be nice to look at.