Yes, very familiar actually. A company I used to work for made hydraulic cylinders, multi stage rotary spools, manifolds, etc,etc. for heave machinery for pressures up to 5000 psi. I did all of their lathe programming. For some of the oil seal grooves that could not be reached with a measuring tool were then tool controlled by having the groove bar cut a land that could be measured. This practice was also verified by cmm. We used this method to control the depth of any and all grooves whether they were on pistons, glands or rotary spools and it proved very effective. If the groove happens to be wider than the tool you are using then essentially you are boring the bottom land of the groove with a grooving tool.
Hi All, First time posting here. Why not finish the bore diameter with the same tool that you are cutting the groove with? That way the groove diameter becomes tool controlled then all you have to really measure is the bore.