Quite often standard steel bore cylinders used chromed piston rings, and on the chrome bore cylinders, standard steel rings, no chrome. It takes forever for chrome rings and chromed bores to seat in.
I had a number of interesting conversations with different companies that do the channel chroming on aircraft cylinders regarding the choking of the bore diameter. C4 cylinders were to have .008" to .010" of choke when new, anything less than .004" was NS.
One company in particular said they had done barrels with no choke and up to .010".
Maximum build up of chrome seemed to be .006"(.012" on dia.) for the repairing of used cylinders.
Regarding chromed rifle bores, most competitive shooters now prefer non chromed bores for accuracy. Hard chrome makes cleaning easier, and greatly extends the life of the barrel.
Last edited by Perry Kitson; 13-02-21 at 16:46.
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