if 8 is flame arrow, they are disabled (you can't spawn them). Use something else.
As for the loop, just think about it... Set a boolean to true when you spawn the projectile and to false next time he gets damage; or check the distance between the points where the player gets damage and where you last spawned the bullet; or check the time interval; or use 32 as the ID for Shooter when spawning the bullet and then check for ID when spawning it again...
but actually you won't get the loop effect to begin with, because Shooter would be the same ID as Victim, because the bullet you spawn belongs to the same player >.<