CZ 527 Lux .223/5.56 ammo

[Dixiejack]

I copied/pasted this from an old thread: [If you want a .223, expect to spend a little more time fettling it, and do not attempt to load to military pressures. whatever you do, have fun.]


I just bought a used 527 Lux in .223.  Waiting for it to arrive.  My question is can 5.56 be safely shot in my 527?  I have a lot of commercial ammo marked 5.56.  I don't know if this is milsup re-boxed.  Some of 5.56 is FMJ and other is HP.
I have read not to shoot 5.56 in a .223 chamber because of the nomenclature of the round. I have a RRA AR-15 that has the Wylde chamber which is OK to shoot .223 Remington and 5.56.  I have also read it doesn't matter. Like to get some expert opinions on my question.
Also, according to CZ-USA website my rifle has a 1:12 twist. What weight bullets will give me the most accuracy?

[ZG47]

Dixiejack
 
Your rifle may safely be used with 5.56x45 ammunition because it is rifled and chambered in compliance with Commission Internationale Permanente (CIP) specifications.  The CIP requires all rifles intended to shoot .223 Rem. and 5.56x45 to have modern 5.56x45 chambers, i.e. suitable for SS109 and M855 rounds.
 
The CIP was established in 1914 at the instigation of the head of the Liege Proof House (second oldest after London) and is an international regulatory body, supervised by the Belgian Parliament in consultation with other European governments and industry groups. The USA's SAAMI, by contrast, is a voluntary industry group with non-enforceable (except by litigation) standards.