For reloading, my process has become fairly simple.
I start off with good components - like Berger Hybrids and Lapua brass, and use powders that are known produce good results in the specific cartridges I reload for, like H4350 for 6.5 cm and H4895 for 6BRA.
My reloading steps are as follows:
1. Tumble brass in rice
2. Anneal with AMP
3. FL size brass, bumping shoulder approx ~2 thou and applying 2-3 thou neck tension. I lube each case with Imperial sizing wax, and after sizing I wipe off excess lube by hand with a clean shop rag.
4. Trim, chamfer and deburr with Giraud trimmer
5. Prime with CPS primer, on the deepest setting
6. Charge on Autotrickler V2 w/V3 board and IP trickler. I aim to weigh to the kernel and get every charge weight within +/- 0.02 grains. (Much harder with large kernels like N570, in which you have to settle for a larger variance)
7. Seat bullets - I typically start 10-20 thou off the lands with Berger Hybrids, and just leave the seater in that setting throughout the life of the barrel. Chasing lands seems to be a waste of time, at least with Hybrids.
With a new barrel, the first 100-150 rounds is barrel break in. Near the end of that, as velocity starts to settle out, I do a ladder test to see what approximate charge weights get what velocity, and where pressure may be. I have velocity targets that I want to achieve with each cartridge - it's somewhat arbitrary, but I try to leave a bit of room below the pressure ceiling. I usually pick a charge weight that gives the approx. velocity I want, to the nearest 0.5 grain (i.e. 40.5 versus 40.3).
Right now these are the velocities that I am shooting:
- 6.5 Creedmoor with 140 Hybrids: 2830 fps
- 6BRA with 105 Hybrids: 2900 fps
- .300NM with 220 LRHT: 2930 fps
I don't do bullet depth seating tests, as through further exploration I've found them to be somewhat useless. At least when shooting with small sample sizes. Extensive testing with different charge weights over numerous days has also shown that specific charge weights don't perform any better when averaged out over numerous days and conditions. Yes, you don't want to be going too slow or too fast, but otherwise specific charge weights don't matter - at least with proven powders per cartridge.