Millets are good--I've got several sets--but I have had trouble with them contacting the receiver like you described. All you need to do is take the little grippers out and file down the bottom of the ring base where the contact occurs. It doesn't take long. If you need high rings you might try BKLs. Because of the way they are designed, I can pretty well promise you that you won't get that contact with them. Good luck.