I agree with Jeff O in that tape is not "essential," but...given the minimal effort and cost involved, why not tape? Why not make the effort to keep out unwanted water, mud, and other debris?
My buddy had a sling come apart this year while deer hunting and his rifle went cart-wheeling on the path in front of him. We were three miles from a cleaning rod. Strangely enough, he didn't plug his barrel with crud, but he just lucked out. I think tape is a good idea.
