Ranged Weapon Projectile damages self

When trying to make a gun mod I noticed that, in survival, the projectile sometimes kills the player that shot it which is undesirable. How I have it wired up is the projectile itself does no damage but instead asks a procedure if it hit a player to do an instant damage effect so I can have a custom death message. Hopefully, with this script, I can simultaneously do a check where if the target entity = entity that used the weapon it won't do damage, else it will. Any way to achieve this?