You can create custom collision channels in Project Settings->Collision if you want to stick to kind of coarse collision but still be able to differentiate between different parts of a single pawn.
Alternatively you could use a hit event which I find to be a little more reliable for kind of thing. and then cast to the player whenever you hit something (better ways to do but for example is simple) and fire a custom event in the player that handles whatever logic you want.
