Re: Am I picking nits?
As I said in another thread, I run a 550b and bought an extra toolhead, a second bushing neck sizing die and a body die recently for my 223 sizing chores. In the seating station (#3), I run the body die, in the crimping (#4) station, I run the first neck sizing die with a larger (.249" or .250") TiNi bushing and no decapping stem. In station #1, I finally have the second neck sizing die, with carbide expander ball and my final X, Y or Z bushing.
I am debating whether to put the carbide expander ball in station 3, without the decapping pin and smoothing out the (often) dinged in AR fired brass, first. It shouldn't be hard to do, as I can back the stem up into the locking piece and use their undersized retaining pin to hold the expander in place.
I use this setup for my .308 bolt gun ammo, sans expander ball and things work smoothly, giving me three steps with one pull of the handle.
I recently bought a Bersin tool for my 7 RemMag loads and will get an extra tool body for my 308 and 223 ammo. This tool has a Swiss made, .01mm/.0004" dial gage which accurately measures runout to four places. Unlike standard concentricity gages, this tool then allows one to nudge the bullet back in the opposite direction of the side with the lowest measurement, slightly bending the bullet/neck interface, for little to no runout.
While I was initially 'learning' this tool, I practiced on some 7 RM ammo I had, first a box of 45 rounds that I loaded with some Hornady New Dimension dies with inline seater. The runout on these was mostly between .004"-.008", with some being below .004", but one I measured was at .011". This bullet would have been keyholing before it ever hit the lands!
Next, I had a box that I had loaded up last year with my new Redding body die, neck bushing die and competition inline seating die and the runout on these 50+ rounds was far lower than the box made using the standard dies.
My chosen 'level of acceptance' is a spread of no more than three places, which equates to a total spread of .0012", or .0006" up, or down, so well under .002" total. For the initial box that I use for fouling shots, I went with a spread of 4 places, so .0016" total--still under .002".
Out of a batch of 20, I didn't need to bump the bullet at all. For the other 15 in the target grade batch, runout never was over say .005" and most were between .002" and .004".
It seems to me, that the Redding dies are better at eliminating runout from the onset, but are by no means perfect.
It's an interesting precision tool that lets one correct the problem after the fact. It took me 15 minutes to go through that batch of 20, correcting 15 of them. Bersin claims 20 rounds in 5 minutes, is all it should take.
The other batch done with the Redding dies was quite similar, but I was learning how to use the Bersin and wasn't taking notes.
Chris