I have called in many does with a predator call both whitetail and mule. The grunt call has worked for younger bucks but the main use I have for it is to stop a deer as it hot foots across a sendero. Just about any call or even a whistle can work but the grunt call may be less likely to spook them.

I think it is like rattling in that there are only a few optimal windows when it will work. Also the buck to doe ratio is critical with usually the closer the better it works.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli