It’s not quite clear what the objective is in the image you provided, but to achieve this:
First, place a Gate node before triggering the shot (have the node’s Start Closed option unchecked)
Then you can add a tag to your actor (make sure that it’s an actor tag tho), break the hit result of your line trace (which you probably use to shoot), connect the Hit Actor to an Actor Has Tag node, copy & paste the name of your tag into the node, connect the Return Value of it into the Condition pin of a Branch node, after it’s True pin, trigger a Set Timer by Event node, and connect the timer’s output exec pin (the white triangle at the end) into the Close pin of our Gate node at the back.
Finally, insert your desired value into the Time pin of the timer, then drag out of the Event pin of the timer and create a custom event, and plug the custom event’s output exec pin into the Open pin of our Gate node.
Hope this helps! 