I started off reloading the Hornady cases from their 55grn red box ammo. I shot it in 100yd matches.
I've been pretty happy with it. Be sure to get a primer pocket uniformer for them, that's one thing they do need, at least with Wolf SRM primers.
I couldn't find a bulk resource though so while I still have 200 cases (recently primed too
) I'm switching to LC brass since that can be bought in bulk (1k) and seems to be the class favorite in Service Rifle Highpower.
My first time case prep with once-fired LC is:
Deprime (Lee universal deprimer)
Clean (though most bulk comes cleaned, yet still has the primer). I use a Harbor Freight rock tumbler using Lemishine and dish detergent)
Ream (cut) out the crimp (Hornady crimp remover chucked in a drill using the Redding power adapter)
Uniform pocket (Redding primer pocket uniformer, comes with handle and drill adapter though I bought a second adapter for the reamer)
FL resize (Lee FL sizer in a Lee Classic Cast single stage)
Trim (Possum Hollow Trimmer with their drill adapter in a drill)
Chamfer/deburr neck (LE Wilson tool which fits right into the PH power adapter)
All done such that each case fits a Dillon 223 case guage perfectly.
Ready to load.
After that you can skip the pocket prep.