Most reloaders who use progressive presses load pistol calibers, but some progressive presses work well for rifle calibers as well.
My Hornady LNL AP with the auto case feeder works very well for high-volume loading of rifle cartridges. For caliber changes just change re-adjusted dies using the Hornady bushing system, then change the shellholder plate, and last, adjust the case-activated powder measure using a micrometer-type adjuster. Very quick and easy. Hornady's customer service is excellent, and there is a lifetime warranty.
I have loaded very accurate .223 and 6HAGAR rounds on the Hornady LNL AP, good enough for a 200/16X score on the MR31 slow fire prone target at 100 yards and for high scores at 200 and 300 yards as well.
Links to a couple of videos that show the operation of the Hornady LNL AP:
http://www.youtube.com/watch?v=_qMg5ysaPz8
http://www.youtube.com/watch?v=5AfKR5cyqi4
I have no experience with Dillon presses, but many guys swear by the Dillon presses. To compare these to the Hornady LNL AP, make sure that you compare to an auto-indexing press. I think (check this yourself!) that the Dillon 550B is manually indexed, and the 650 is auto-indexing (like the Hornady LNL AP). To compare apples to apples, also check which models include the automatic primer system and a case-activated powder measure.
Link to Dillon video:
http://www.youtube.com/watch?v=k0__OViMcaA&feature=youtu.be
My advice is to do your homework - do a lot of research. Compared to a single-stage press, there is more of a learning curve with the progressive presses, and you don't want to spend many hours and realize that you may have made the wrong choice.
Here is a link to an EXCELLENT comparative review of the Hornady, Dillon and Lee progressive presses:
http://www.comrace.ca/cmfiles/dillonLeeHornadyComparison.pdf
Pay particular attention to users' experiences with the powder measures of the Hornady vs. Dillon systems.
I'm very happy with the Hornady LNL AP with the automatic case feeder and case-activated powder measure, and can recommend it highly.
Randy