I never found a blem either but I did order 2 (blem) stainless Freedom kits without the receiver years ago and a buddy got the same part number I did.
But his chamber is much tighter than all mine.
I can run minimal sized bolt gun ammo in mine and his needs the shoulder pushed back .005" or more to allow the rounds to chamber.
So could the "blem" be chamber dimensions not quite spot on.
Still shoot and still plenty safe.
