I have never hunted elk with anything other than a bow, so we are looking at Aug. and Sept. time frame. The three things that effect the way elk react are, #1 temperature, #2 moon phase, #3 hunter pressure. If the days are too warm elk will go nocternal, they just can't take the heat with winter coats coming in. So the time in the morning and evening when they will react to a call is short. Unless you are in the way of where they want to go. If the moon is near full or full, they my call all night and rest during the day, so you get no real reaction from them. If there are a lot hunters calling, the elk will move off or go nocternal. Now if the weather is cool to cold and no one is bothered them too much, the cows are hot, the bulls go nuts and your calls work great. But to get herd bulls to come to a call and leave his girl friends, you have to do one of two things or both. Sound like the hottest piece of meat in the world that he just can't live without. Or you have to call his cows away from him so he is looking for a fight. This is not all that easy to do, but can be done. Just some insight from my hunting and calling elk. Keep a note book of time, weather, moon and hunters afield when you have luck calling in animals, see what you think.
Gselkhunter