Re: Question bout Wylde chamber
As others have said: full-length size each loading.
You are shooting an AR, not a bench rifle. If you are looking for an advantage in accuracy from neck-sizing only you shooting the wrong rifle.
I not only full-length resize, but I full-length resize with a small-base die and go right back to SAAMI spec. I do this to ensure function in a number of rifles, all of which have Wylde chambers. Doing this does shorten brass life as some cases will be set back as much as .006, but it does not affect accuracy.
FWIW, a Wylde chamber varies from the standard .223 Rem in that it has more generous cartridge body dimensions, a longer throat, but the throat diameter is smaller. Variants of the Wylde chamber are the AMU (.030 longer throat to put the base of the 80 Sierra at the shoulder junction) and the Holliger (.060 longer throat for case capacity with 90 grain bullets).