I am preparing to set up on a Dillon 550B. A couple of questions. I will be using Redding two die set w/FL and seater dies. However I will be using fire formed brass and am getting the neck die as well. First question is should I be getting the "bushing type" vs regular neck die? Is there a $30 difference in my reloading that will be for hunting almost exclusively. Next if the bushing die is the one I choose, they suggest I measure the diameter ofa "loaded round" in order to get the correct bushing. Will a fire formed case unloaded work for this measurement?

Next, will a universal decapping die work with the dillon 550B toolhead with dies already in three of the four positions on the toolhead or must it be done separately? Thanks for sharing your knowledge.

I think reloading for a hunting firearm should be left to standard dies even when neck sizing. Leave the bushing dies to the benchrest guys as they have the patience to be annal about every aspect of every detail down to a gnat's ass. Why do you need a universal decapping die? Those dies are used by guys that want to decap and then tumble the brass. A standard neck sizing die will decap and reset the neck diameter to the correct dimensions. What you may need for a progressive press is an expander die which would flare the mouth ever so slightly so that the bullet will set on the mouth without being held while entering the seating die. When loading rifle cartridges in a progressive I use a crimp die to straighten the flair back out without actually crimping the mouth. I don't load on a Dillon, I use a Hornady LNL AP but really they perform the same steps. BTW, I have heard that the Dillon presses really work better with proprietary dies, i.e: Dillon dies

Forgot to mention, you need to measure every case for length and trim as necessary. The manuals give .010 under Max case length as the "trim to length" but I only go .005 under, but thats just me being superstitious.

Dennis, thanks for the input. You are correct I was going to decap and then tumble brass. When do you tumble?

Just a little input uni decapping is good if you do a lot of brass that is crimped primers. The pin in the uni decapping dies are a little heavier than in the resizer. Tumble before and after sizing maybe. depends on the lube that you use and the way you process. If you use a uni decap then you could tumble after, but beware that you can have media stuck in the primer pockets and flash hole. also the media can cause headaches with your primer system on your dillon and also on the L-N-L press. If you are going to size and decap on the same step always tumble your brass the grit that is on it isn't good for your dies or the brass. once you size it then you can tumble it again to get the lube of or you can wipe them all down.

also yo will find that tumbling brass doesn't clean the primer pockets that great. If you save your pennys get a trim mate by RCBS and a primer pockets uniformer this will clean them up nicely and also the obvious uniform the primer pockets. then at each reload us the trim mate with a primer pocket brush.