Upgraded my 550b to a 550c. WOW! Smother running machine. The only downside is you have to go to Youtube to watch a video on how to make the conversion properly.Dillon RL550b here. Been doing it for decades.
Well after 25+ yrs mine runs as smooth as it ever did. Is the C upgrade just the grease zerk? My 550b also does not have that grease zerk on the pivot arms/ handle holder as the youtube video on his. If yours has that it's much newer than mine.Upgraded my 550b to a 550c. WOW! Smother running machine. The only downside is you have to go to Youtube to watch a video on how to make the conversion properly.