Gordo,
The piston you show looks like it started seizing in the cylinder. Many piston manufacturers suggest .002 to .003" clearance and for a solid skirt piston, that is too tight. I usually hone to .0035" for a street engine and .004" for a performance engine that will be worked hard.
If your clearance is down around .002", you will have problems.
I am sure some others will chime in on this subject.
Good Day!
www.durableperformance.net