For patent drawings, It would be nice to have leaders with no arrowheads.
In utility and provisional patent drawings, the style is to have no arrowheads unless you are pointing at an assembly, or a group of parts.
Attaching some example utility drawings
http://www.skeletool.com/images/content/utility/7249390/Patent%207249390%207530129%20Surge%20Scissor...
http://www.skeletool.com/images/content/utility/7347128/Patent%207347128%20Charge%20Perspective%20Op...