All the ones I have on hand step down to a very small spit hole through the rod, no matter what size the bottom of the hole is. Maybe it's just a safety factor to make sure the hole in the rod bearing lines up.
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!