i'm a minimalist reloader. my buddies call me lazy. while others were doing weeks of case prep and load development when i shot ihmsa, i just wanted my load to be consistent enough to hit a 2 foot square at 100 meters. again my buddies were comedians saying i strived for foa perfection. that was "foot of angle." the chronograph was my friend cause i agree with this guy...your loads need to be consistent. we chased that decent standard deviation. this was for a xp pistol and contender, barrel length 14". never shot that perfect 40 but had a ton of 39's. i wonder sometimes if i went that extra bit of prep would i have gotten that 40. but all my case prep pals were mid 20's at best.
i don't think i've ever trimmed a case in my life. i'll tumble and i ream the primer pocket of carbon so the primers seat evenly hopefully every time. i set the primers with a hand tool, i like to feel when they bottom into the pocket instead of crushing them with the press handle. so this primer ritual is my thing to try to get consistent ignition. of course i don't do that if i'm bulk loading range ammo using a progressive press.
once i tried to measure the case capacity, you know, weighing the amount of water the case held. i did 2 and said f*** this. same with neck thickness. if anything glares out at me i just cull the case from the herd.
i think
@mac1911 said it above...it's between your ears.