One thing you have to remember & I'm sure you know , is , the 308AR's are a different animal than the .223/5.56 . Might be because its a .308 & the power of the cartridge may have different characteristics .
Did you check head space before you Reamed the Chamber ? By all means test live ammo in different configurations & see how it works out , I'm curious & would appreciate the results .
It is very time consuming working up a load , I just spent about a year setting some up for my 20' & 16 " 308AR's .