its not the grunt most likly because there is alot of good grunts out there!! some deer respond and some run away some do nothing .it al depends on what mood hes in.if hes on a doe good luck!!!nothing will get him to come other then the doe hes chasing. one thing i do is dont call to much so that he dont get a fix on your postion.if hes coming to you dont do nothing.if hes going away try anything like bleating, grunting or even a little rattling.but it all comes down to how much you do it and what your buck to doe ratio is!!!!!!!!!!!!!!!!