t6 ghom need build for single target - Demon Hunter - Game Guide - Diablo III
but M6 Sentry build not really good for Ghom.
replace equipment and put:
2 Aughild's [ shoulders + chest + bracers ]
2 Blackthorne's [ waist + legs ] or anything you have
Unity+ SoJ + RRG(mast have) + fire dmg...