I load them one at a time. I'm not loading lots and lots of bullets either. But then it gives me peace of mind that each one is as close to identical as I can make it.
One at a time...like a machine. I deprime, tumble, resize (wipe case), trim (yes, every time), chamfer, prime, powder (weigh each load), seat (a trick is to seat 3/4 then rotate case 90 degrees), check length, then crimp with lee crimp die. I make perfect ammo.
I also do one at a time and measure everything. I rotate the case as stated above and rarely have much measured run-out using RCBS equipment with a few minor upgrades.
One st a time for all my rifles I have OCD and each of my guns has its own load and they have to be the same once I find the load I like takes me a while but it’s worth it