RE: How long until he's back???
He may well come back in a day or two, heck, maybe even tomorrow. However, if you were calling to that bird and then shot at him and missed him, it has been my experience that he may well NEVER go to a hen again. Certainly not this season anyhow. As for gobbling....little if any.
Every bird is different. Yours might not have a care in the world. I have called birds back immediately after shooting one with a fighting purr and taken a second bird as well. Sometimes they care, sometimes they don't.
To use generalizations however instead of exceptions, I would limit my calling henceforth. I'd use a different pitch call, if a different rythm from a different spot. When a gobbler goes againest the norm and comes to a hen instead of vice versa and is rewarded with no hen, or to a greater extent a load of shot flying past his head....he doesn't tend to make the mistake twice.... Good luck.