Quick follow on, to the above from an "official" source...
TM 9-1802A (June 1943) Par.60, Sec. C (1)
Fit Piston Pins in Pistons says:
"At normal room temperature, piston pins should be tight in pistons, but at normal operating temperature, piston pins will be floating fit in pistons and connecting rod bushings. When piston pin boss is accurately reamed, piston pin cannot be installed in piston by hand at room temperature of 70 degrees. Pin should be a smooth "hand press" fit in piston after piston is heated in water to approximately 30 degrees above room temperature.* Pin should fit into piston freely after piston is heated to approximately 170 degrees."
* I guess 4th echelon maintenance units weren't equipped with hair driers back then.
Best Regards...
