Using this tutorial : [Unreal Engine 4.10] Grappling Hook Blueprint Tutorial - YouTube i was able to replicate the effect on the third person base project but i run into two problems.First and most important is that the hook will always shoot towards what i believe to be the initial world location(0,0,0) which seems to be in the middle of the map,no matter how many timesi repeat the action.it seems to my noobish eyes that it has something to do with the line-trace part of the buttleprint.second problem is that i can not seem to locate the supposed speed that the line shoots out at.any advice would be deeply appreciated 
Hi,
Do you have your Trace Channels set up correctly? Make sure that your actors are using the trace channel that you are tracing on. Also, in my experience you cannot line trace ‘into the void’ so the trace needs to hit an actual object to return a valid hit location.
I hope this will help you.
I think the speed that you can’t find is the Interp Speed of the VInterp to?
As for the strange trace orientation, try using “Get Player Camera Manager” and using a Get Camera Location and Get Forward Vector from it, instead of tracing from the follow camera.
I have seen a couple of other users having a strange orientation result on their traces when using the third person example and tracing from follow camera
See this thread: Solving Line Trace Jitter - Multiplayer & Networking - Unreal Engine Forums
Might have something to do with it.