I've been reloading, off and on since '69 or '70. 90% of my reloading has been handgun ammo and as long as the primers don't stand "proud" and seated to the bottom of the pocket, there will be no problems. I don't believe I've ever measured a primer depth (I have 30+ years machinist/mechanic experience and am fully aware of how to measure). Common sense is all that's needed; the anvil seated properly to the bottom of the pocket, a firing pin strike will crush the compound between the anvil and the cup without seating the primer deeper in the pocket.
As for checking and double checking; you know your initial measurements and settings. Keep measuring and checking to eliminate that OOPS! that can cause damage to you and your gun. Set your powder measure to the desired powder load and check it often. I would be silly to check once and load 100 cases without rechecking. If you set your OAL for the first cartridge, it would be sloppy reloading to not check again. Of course there will be variations, but you will know your tolerance, plus or minus, from your initial settings. It is all about being safe. Don't overthink the process...
The fellers here are just trying to help, so why dispute or be so critical of the answers you get? Post #4
My Anchor is holding fast!