How fast are your bullets?
and make a line trace each frame
This may not be enough, if you cover 1 meter in 1 frame, you might miss a headshot.
Have you considered using Mulitsphere Trace for Objects, it returns an array of Hit Result structs.
Since you know the bullet velocity and distance, you can tell the time of hit, too. Once you have the data, you can calculate the possible penetration outcome and send the bullet flying to the last unpenetrable location.
This will not work great if the target is moving fast and the bullet is slow since you’re checking for collisions here and now rather than over there and then.
If you’re using physics for the bullets, there is an advanced projectile prediction node that does the time calculation automagically, it takes custom simulating frequency as input. Never used it for anything professional, though.