Before you damage the plastic primer pickup tips to get them off the tubes, try applying just a little heat from either a blow dryer or heat gun. That may allow the plastic to expand enough that they can be removed without damage. I've had my 550B for over 20 years and love the manual advance as it gives me more control of the process, especially when there is a problem, it simplifies clearing the problem round. Only problem I ever had was from me over tightening the (2) primer assembly bolts. I was getting primers flipping over, hanging up and failures to feed and it was driving me nuts. After looking everything over the setup from beginning to end & knowing my tendency to over tighten things I figured out where I was screwing up. Completely from me using too much umph.