Contrary to anime lore, spinning a staff in place would actually be a terrible idea for deflecting bullets, since the staff wouldn't actually become a solid circular object when spun. Unless you plan on getting obscenely lucky every time someone shoots at you while you spin the staff, you'd have to have it moving many, many times the speed of sound in order to create an even semi-effective barrier, since it would have to be able to complete half a rotation in less time than it takes for the bullet to travel an inch (and then you have the same speed problem as blocking bullets after they're fired, since that level of speed would mean you can hit like a runaway bullet train). Moving the staff to block where someone's aiming would be the better method by far.