. . . something has to be sacrificed. Powder choice or charge accuracy might be among those things lost.
Rocky,
The exception is the one you lead me to a year (or is it two, now?) ago that I mentioned in post #2. Get the JDS Quick Measure and its Dillon adapter. Not an inexpensive solution, but will keep the drops within .1 and sometimes .2 grains, worst case, even for the very coarsest stick powders. Since this is a rifle with jacketed bullets, as long as he applies a chamfer to the case mouths, he won't need an expander step, and the 4-station 550B will still do the job.
Mcg6637,
The Quick Measure is the Cadillac solution, but before going there do try the extra powder baffles and a one or two second burst on the fish tank pump that I mention in post #2.
One additional consideration on progressives that I saw recently (but can't recall the source): the author commented that he sees a difference in shoulder setback and seating depth until all stations on the progressive press are full. It's a difference in the press flex under the changing loads. You need to figure that on a press with
n stations, your first and last
n-1 rounds might be slightly different and should be set aside as fouling or practice loads. That is, your first and last two on a three station press, your first and last three on a four station press, your first and last four on a five station, etc. Also, you need to double-check that the ammo coming off the press after the stations are full are measuring what you want them to.
On the Dillon 550B and its predecessors, you can use its stations as a single-stage press by not indexing if you choose not to, or by pulling the brass buttons and removing the sized case on the 650. You can size all your brass, trim, chamfer and clean the lube off, then start them into progressive completion by priming then indexing normally for the other stages. You may get somewhat more consistent sizing by keeping that step separate and the other stages probably won't notice the load difference much if you do that. Experiment.