Accurate will be the mold maker and my dies will be used in a Dillon 550.
I've been extremely happy with the molds I've obtained from Accurate. I think that's a solid choice. That leaves mold material, number of cavities, bullet weight, and bullet profile; for your mold decisions.
Mold material (iron, brass, aluminum) is a topic all to itself. That ground has been covered before and I'll leave that alone.
Number of cavities - For handgun bullets, I like 4 cavity molds, YMMV
Bullet weight for 10mm, I don't have a lot of time in grade with 10mm but I have a little. 180 grains seem to be about the sweet spot.
Profile - Truncated cone is a very universal profile when it comes to pistols (as opposed to revolvers) and gives you a flat nose. Good feeding and functioning with a flat nose.
As for dies in a Dillon 550, Lots of good choice available here. I routinely mix and match dies in a 550 toolhead. There's no need for the dies to all be the same brand in the tool head.
The sizing/decapping die (station 1) needs to be a carbide die unless you just like lubing cases. A generous radius on the die mouth helps with the operation of the press. There are plenty of choices here. RCBS, Redding and of course Dillon's own dies come to mind.
The powder through die is a Dillon die with an expander in it. (Station 2) That expander really should be one of the custom expanders with the Lyman Type "M" profile. There are a few choices, but this is one place where Dillon fails. The Dillon expanders produce a flare on the case mouth, not a step. And the Dillon expanders do not expand the neck adequately for a cast bullet. IMO
The seating die (station 3) is not critical, but the nose of the seating stem should be compatible with your bullet nose. The stem on the new style Dillon dies can be removed and cleaned without disturbing the die setting. That’s a nice feature.
The crimping die (station 4) needs to be a taper crimp for 10mm Auto. Lots of choices here. I like Redding. It’s pricy but it is a 1-time cost. Frankly, just about any brand will work and again, Dillon may be the simplest/cheapest choice here.
