Hi, I have a home grinder I made from a kit in the early 70's. It has five and a half inch stones. I'd like to replace them. Every once in a while in each two loaf batch I get a tiny particle of grit in a bit of bread [maybe twice or so per loaf]. The stones are mounted correctly and never touch each other. Even on the finest setting they don't rub. This is adjustable on my mill. It isn't much of a problem they are always too small find again if you keep on chewing. But it bothers me that the slugs who put this kit together were too cheap to use a stone that was harder that wheat! Is this a common problem with stone mills? It's the only one I've ever had.