How to avoid self collision with projectile in Multiplayer

Hello guys! Could anyone help me to solve this problem please my projectiles always collide(and thus decreases HP) with my own pawn ,and I don’t know how to “teach” my projectiles to avoid it. “Cast to” my actor and than check wether he collides with projectile or not isn’t working cuz I have Multiplayer game and all players have the same actor BP.So when they connect to the server they are given the same actor class and here I can’t use “cast to”.I would greatly appreciate if you give me tips how to get the instigator of the event in MP game in my case it is an actor that shoots projectile in Multiplayer session . That would solve many problems. Thank you.