I've mentioned this before and it bears repeating! To be effective on 90% of your elk encounters you must understand what elk are saying! You must understand what you're saying when starting out in the morning or responding back. It makes it much easier to hunt them and not turn them into runners.

For example--(not picking on anyone) Skeeter, you say you "locate" bulls first then move in and finish them off with cow calls.---First, what did the bull that responded say? Was he welcoming you? Was he challenging or intimidating you to stay away? Was he talking to his harem because of you, in other words trying to gather them up for possible escape because of not wanting a confrontation? You see once you understand what he said, it's much easier to form a strategy. Sure, by moving in and cow calling may work one out 4-5 bulls you come across, but what about the others you blew, it didn't have to be that way.

You also mentioned that after moving in on a bull and cow call and if he's "hanging up", you mimmic the bull as he's bugling you, most likely with short screams. This bull isn't challenging the cow, he's trying to call her to him, so for you to respond back with the exact sound he's using, it doesn't make sense to him. --- But, if when cow calling (pre-estrus whines) and he's not coming in, let him know why or else he'll get nervous and be gone. This is the time to throw in some huffs to huffing grunts, this is what a real bull would do if he were to intercept this cow on her way to the real bull. This method is non challenging, the huffs are directed to the cow not the real bull, he knows that. But yet the real bull won't stand for it. Along with the huffs you might increase the the level of cow calling to distress sounds, it shows resistance on the cows part to the fake bull who's huffing in desperation to leave with her. If it's a herd bull you're dealing with you must be in close for this to be effective, (inside a 100yds) he won't want to stray too far from his cows just to pick up one more, so make it convienent for him.

As far as making chuckles & grunts, it takes practice. Chuckles are generally used within the herd to communicate with his cows, they can also be used to call cows to him, whether trying to call in a lone cow or if they've been spooked and they all scattered in different directions. The bull would stop, and start chuckling to regather his cows.
Grunts are for intimidation or warning. ---Chuckles are low keyed, squealy and rapid---Grunts are throaty, deep and hard hitting, almost "base" like sounding. At any rate, pull the air from your stomach or diaphragm as you blow into your tube.--elknut1