Sizing is just what we HAVE TO DO for chambering, eventually.
Traditional FL sizing doesn't hurt if your die matches your fireformed ammo(minimal sizing). This just can't be assumed to happen by chance though.
It doesn't hurt to size the necks and body seperately either. I use Wilson neck sizing, and JLC body dies in 223, 6br, 6xc, and 6.5wssm. A couple of these are neck turned, and I never size more than a cal of the necks. Just no need to.
I've been very happy with body dies messaged by JLC. Similar to these:
6mmBR.com Reviews of Reloading tools, Bipods Harris Pod-loc, Cleaning Supplies, Redding Wilson Dies, K&M Tools, Neck turning Tools, Shooting Accessories and supplies.
His 6xc die compelled me to throw Tubb's in the trash. He recently cut a body die for my 6.5wssm with my finish reamer. Not sure how he does it, but my sizing perfectly matches my chambers. Around .001" under everywhere except the web, which I keep at .0005" under.
This is great provided your pressures are normal(55-65Kpsi). Brass lasts forever.
Point blank BR shooters run way higher pressures though, and must size the webs heavily or open the chamber there for reasonable extraction.
BR shooters also FL size because the bushing system we use today is a bit from perfect still. And a custom FL die will produce straighter ammo.
Does Hornady produce custom dies like these?
As implied, this does not happen by chance.