I hunt the late archery season on the westside and have heard blacktail bucks grunting on several hunts. I rarely hear a grunt beyond 20 or 30 yards, most grunts are pretty soft. Seems like mature bucks grunt almost constantly when they are chasing a doe. I have grunted a couple bucks in, but no shooters. One was a small 2 point that walked in without hesitation and gave me a broadside shot at 9 feet. I passed on the shot, but was happy with the response to my grunt call.