Having fun experimenting with my lens collection on my new D7100.
At the moment it is sitting in front of me with a Nikkor 55-300 AFS and a Kenko 1.4 T.C. .
Found that combo works better than the Tamron 70-300 which I thought strange as Kenko and Tamron are related companies. I did check - there is lots of clearance - no fear of lens to lens contact at 55mm.