Yes, some may close on a .223 Rem FIELD but not a USGI FIELD.
USGI FIELD is 1.4730"
.223 Rem FIELD is 1.4700"
As mentioned USGI 5.56mm FIELD is more forgiving.
Just for shits and giggles a M249 SAW 5.56mm FIELD is 1.50216" which is why I have repeating have said not to reload or shoot reloads that are from military brass that has gone through a M249 SAW or any belt fed machinegun.

