Hey Joel, how you been, it's been a while bud!(grin) I agree 100% on that sound to be dynamite in ones efforts to call a bulls cows from him, it can flat tick him off as you question his right to keep & breed his cows. Guys it flat works & is our # 1 sound especially when there's signs of a hot cow in the harem. If there is not a hot cow in the harem you'll know because the herd bull is pretty laid back & allows satellites within his group & he is not bugling much. Too, he's not very vocal & satellites are not harassing him & trying to call his cows from him! If you try to be too aggressive when herd bull is not ripe (no hot cows) it can be a real crap shoot to trigger him! I generally pull out the "curiosity card" at this time!
AKBowman, to your question, it's situational. If there is a hot cow & the bull is where he wants to be such as his bedding area he can defend to no end! This is where closer is better but 150yds is not out of the question if the hunter cannot get closer because of lack of cover. At that distance you have to put the pedal to the metal & convince him you have one of his cows! If you can get close to the group as Joel mentions that is money at this magical time!
We've run at the cows before to run them off, once right where the cows were we use that Bugle tone trying to call them back, this can have the herd bull explode in a rage of fury & come in on a string! Of course turning to that course of action means the herd bull cannot see or smell you! Yes, there are variables & hurdles to over come at times but with quick thinking & action you can get it done!
p.s. when calling to elk in the open as you mentioned above it's pretty much a losing battle! Try to shrink back from calling to elk that you can visually see. You see them & they can see where the source of sounds are coming from & not see elk! They will bugger! Wait till these elk slip into cover then get closer & then call if need be to redirect them with specific sounds!
ElkNut1