Re: how do you properly lubricate a Dillon 550B press?
Every 1000 rounds or so, I lube the main shaft with motor oil, like the manual says.
With the shellplate in the down position, I take a paper towel and wipe all the old oil/powder residue off the lower part of the shaft (below the frame), then pull the handle to put the shellplate into the raised position. I then wipe the upper part of the shaft off. With the shaft/shellplate still raised, I just pour a LITTLE (just enough to get fingertip wet) motor oil on a fingertip, and rub it around the bottom few inches of the shaft as it goes into the frame. When the shellplate is lowered, most of this will "squeege" off, but some will hopefully get into the bushing. It really doesn't take much.
I put a dab of axel grease on the first few threads of the big bolt that holds the shellplates on every now and then.
I don't use any other lube, but will probably get some silicone spray to use on the bottom of the primer slide assembly next time I see some on sale.
I think aside for the main shaft, less lube is the way to go. If things are dry, spilled powder and dust cannot stick and gum things up.