I have a Dillon RL-450 that I bought new in 1984, I have loaded over 100,000 rds on this press. I have had small issues over the years that Dillon always took care of promptly. I sent some components in for work right before Christmas, The primer feed base screw threads had gotten fubar. The 450 feeder is no longer made and the 550 feed is slightly different. The fine folks at Dillon Precision graciously sent me a complete primer feed set up for the RL-550! I am now back up and running with upgaded parts. They continue to stand by their no BS guarantee.