This is the same piston I've had since I rebuilt this engine 5 years ago and I have had 3 different cylinders since then. None of them broke on the inside. All of them broke on the outside.
BUT... Seafoam is my answer I accept not having to do the work. Thanks!
If that is a 5 year old piston then you haven't been totally mistreating your engine. There is minimal blowby at the ring gap, but that's beyond expected for a trooper like that.