Can't speak for factory loads in Lake City ammo, but I sure use a lot of Lake City brass. I have some brass that is stamped Lake City from the 1960s. Lord knows how many times they have been reloaded.

always worked fine for me.

I shoot military ball, that "white box" 5.56 stuff and and 223 rounds in my CZ 527 varmint rifle. I get 1 inch groups (3 rds) with with the "white box" ball. Less than that with Hornady V-Max. I had the same question you did before I purchased the rifle. I called CZ, they said don't worry about it the rifle could handle the different pressures. "Cartridges of the World" 7th edition say," In 1979, SAAMI cautioned shooters that 5.56 mm military chambers and throats differ from 223 Reminton sporting rifle chambers. Therefore military ball ammo may produce high chamber pressures in sporting rifles".