I've had good success using a grunt. I use the primos original buck roar. My biggest buck was killed using a grunt. I was watching a spike and a 6 point 200 yrds away in a 2yr old clear cut to see how they would respond. I played with them for 5-10 minutes. When they would start to walk off I would grunt one time and they would stop and stare. They never would start to come may way, so I let them wonder on off and enjoyed my encounter. When I pulled the binos away from my eyes I caught horns gleaming in the sun out the corner of my eye and he was standing there like a post card picture. He was looking in my direction trying to find the buck that kept grunting. It's my avatar pic.
I used to blind call with not much luck. Now, I only call when I see or hear something. Like others have said, only call to get their attention and then go quiet. If they continue to walk away, call again. Sometimes they come closer, sometimes they circle, and sometimes they just don't care. It's a useful tool if used right, but not a given. I think it's all in their current mood.
