The recommended approach is to use a tolerance if you must, or ideally just to not care. You can do raycasts on the client to anticipate visual effects and stuff, but leave the authoritative logic to the server, like the raycasts that inflict damage.
You can see a good example of this in the Shootergame example, which you can download from the Epic launcher under the “learn:” tab, all the way down under the games section. This is a good starting place for learning how to do a shooter.
The documentation covers a good amount of detail as well of the separation between client and server logic