Quoted:
You need two dies to use a rotary chamber powder measure on a Dillon;
1. The 450 adapter die
2. The powder die
I have a Redding BR-30 I use for rifle rounds. I started out with a stripped 550-B, called the AT-500. I built it they way I wanted it straight for rifle rounds from the beginning. I resize on a single stage then trim on my Giraud. I prime on a RCBS bench mounted priming tool. The AT-500 has a Sinclair International expander mandrel in station #1, Redding BR-30 powder measure at station #2, a Redding or Forster benchrest seater in station #3 depending on caliber and in station #4 I use a Lee's Factory Crimp Die if I crimp at all.
You have to be very careful and visually insure that you charged each case when using a manual powder measure. It will not charge the case with powder as a function of working the handle, I wish you could. It is easy to lose concentration and not look for the powder in each case. If I'm not sure, I'll pull the suspect round and weigh it to make sure it got it's powder.
I like Reddings BR-30 much better than Dillon's powder measure (who wouldn't) but it is not perfection yet. Sometimes I feel like the Wizard of Oz pulling all the handles, tweaking everything and double checking my work.
Sir, FWIW it's amazing how much our techniques are alike. I use a Redding 3BR at station two of my Dillon 550 when reloading .223 Rem. and 260 Rem. The powders that I use for those cartridges, VV N540, and H4350 simply will not meter satisfactorily from my Dillon powder measures, regardless my having polished the Dillon measure much as is shown in the tacked threads at the top of this forum page. I determined that much as Dillon says in their Blue Press, their powder measures are not intended for "long grain extruded powders" so the powders that I choose like IMR4895, IMR4060, and others are best metered from my Redding powder measure. You do have to be observant when charging cases this way, especially with cartridges with small neck diameters such as .223 Rem. the inside throat of the Dillon powder funnel has to be polished and possibly reamed to ensure the individual grains of powder do not bridge around the funnel hole and block the flow of powder. I've considered mounting a powder check die at station three of my Dillon 550, but it appears trying to seat bullets on station four would be too ackward.
I do use my Dillon powder measures for other cartridges, mostly pistol. They work quite well with H110, Unique, WW231, AA7 etc. FWIW as a long standing Dillon user going back to my first RL 450 the Dillon powder measure has been somewhat of an evolution all by itself. That's one of the reasons I bought an XL650, I can use that press to load other cartridges without disturbing my 550 which is already set up for reloading match rifle cartridges. JMHO, 7zero1.