Quote Originally Posted by Vapor View Post
In the same family as the sleeve bearing is basically all I know. Supposedly longevity of ball bearing and low noise of sleeve...not sure about positional deficiencies though.
I think rifle bearing is where they put rifling into the axle, which in turn causes it to act like corkscrew, moving oil constantly around the axle. It's supposed to solve the problem of sleeve bearings being mounted horizontally. Check it out on wikipedia.