After 25 years I considered doing the same thing. But I am set up to load 10 different rounds and am heavily invested to start all over. So I decided to just get a second 550b to have a dedicated machine for both SP and LP. I’m glad I did it. As stated earlier, the Federal SP .45 cases really threw a wrench Into the auto case feeder... and without it the 750 is nothing more that an auto indexing 550. However for SP cases the 750 seems like the bees knees.