"Buffing" means to rub off the corners so that the die won't stop until the side with the right numbers is up. Like sanding or shearing, cutting off a little bit to throw off the balance.
It is called 'loading the die' too, although if you actualy 'load' a die, you drill a hole in it and fill it with lead, so that the weighted side will always land down.
Makes you wonder where Mac learned all this stuff from... Bill Cody, maybe?
Everyone, sometimes, needs a camel.
Old troubleshooters never die...
They just wait til the last moment and then rescue themselves!