To err is human
Errare humanum est
what would be a good translation for
To throw (a stone or projectile) is human
I'm looking at proicere humanum est and mittere humanum est; proicere parallels with 'projectile', and mittere parallels with 'missile'.
In particular, the context of this is more in the
drop a stone down a well to figure out how deep it goes
throw a rock at a bird for hunting