Hunting rifles should have a jump. Largely, that's to let you load and unload without worrying about pulling the bullet if it were jammed into the lands. It also gives you a bit of a "safety factor" for thermal versatility in a hunting rifle that might find itself hunting a very very cold morning (powder cooks off a lot slower) or hunting a mild and sunny afternoon. A load that's safe in cold weather when kissing the lands might blow your rifle apart on a 60degree day.

I know that I don't have any loads in my "cook book" that run a 30thou jump. I start at 20 thou off to do my early load work, then work my way in, usually end up between 0.015 to 0.005 jump, depending on my application and how often I tend to clean a given rifle. I used to jam 10thou in my bench rest rifle, but I don't load any that way anymore.