I only have about 200,000 rounds reloaded on mine and the pivot holes on the chute are still good. I did experience a new problem with primer seating about a year ago when it wouldn't seat a primer. I looked for all the usual suspects and then I noticed the handle was going too far forward. The cast piece that the handle, link arms and ram attach to was cracked. Dillon sent a new one that day and I was back up and running later that week. The new part was built with heavier reinforcements and sides. Maybe that and the lubrication holes for the shafts was the difference between a 550 and a 550B. You have to love their "No BS Warranty".