Another sneaky trick to get better performance from drums that aren't original diameter is to glue a piece of sandpaper like one for a body shop air file to the inside of a drum, and scuff the lining contour to the same arc as the drum. It eliminates the "wearing in" process that needs to happen when a standard-diameter lining works against an oversize drum. Use a water-soluble glue like original Elmer's, and getting the sandpaper off once the linings are fitted is a lot easier.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!