also keep in mind a grunt can be used to stop a deer that has been shot.
Last year I rattled in a small forkie, and the shot ended up a little high (above the shoulder blade) angling down and towards his last rib on the other side. he had stepped sideways and slightly toward me on release....I wasn't totally sure there was an exit hole (probably got about 15" of penetration)....so when the deer bolted, I grabbed my grunt tube and hit it a few times. he stopped dead as soon as I grunted...looking back, and a few seconds later I watched his legs go wobbly and over he went.
and glad I stopped him, cause there wasn't an exit, no blood trail and he was heading towards a swamp. he would have been dead in a few seconds anyway cause I got both lungs...but who knows if I ever would have found him.