When projectile hits the character, from the “Event Hit” we call the function “Try To Dismember” with parameters from the event: actor (it must be Character), bone name and hit location.
Since, you probably don’t have “Event Hit” with using melee weapon, when u swing through character, you should artifically call the standard node “Make Hit Result” and fill its parameters (actor, bone, hit location). That’s all that is required to change projectile to melee. Just have to adjust your melee weapon collision to get these 3 basic parameters.