Go too low with the rakers, and you'll make it jumpy, ruining a good chain. A good chain is smooth in the cut and self feeds itself, requiring very little if any pressure. I like to grind my chains, then touch them up with a file in a Granburg File-N-Joint. I then use an Oregon progressive depth guage. I find that the File-O-Plate sets my rakers too deep, at least on Stihl RSC chain.