How to get range on a dog?

First off, way to go, keep up the good work and don't get too frustrated. With your commitment to consistency, they will come around to their new way.

Gotta add though, I don't know your situation, but I know back when I walk hunted all the time I got ahold of some really nice dogs and very quickly knocked the range off of them by walking with them. I'm not assuming everyone who walk hunts will knock the range off their dogs, but I know I did by complete accident and didn't realize it till a few years into that method.
Now we cuaght gobs and gobs and gobs of good hogs and they always showed bottom, but it did knock the "free casting" range down on the dogs I was given.
Once I went back to roading, their range picked up a little, but not much, these days though I am commited to strictly casting them for the time being and in almost no time I have seen desired results.

Keep it up friend, best of luck