Originally Posted by sigma6
As a general rule is it better to use Nato brass or .223 brass for MK262 clones?
Use whatever brass you can get your hands on. I like LC and Rem.
24 TAC + 77 @ 2.245 is closest I got in LC brass.
You are much better off picking a more temp stable and accurate powder like varget H4895 etc and developing a good load than trying to clone the mythic Mk262.