[blykins]

Unless it's a Keith Black hypereutectic, that data is not correct.....

I buy pistons by the truck load, gap the rings at .0045/.005 per inch of bore and don't have this trouble.

To the OP:

If you pull the piston out and all the ring gaps are lined up, that's another sign of detonation. Also check out the upper rod bearings and lower main bearings. You can also have some piston/head clearance issues which will hammer on the ring lands.