November45

Hello everyone, I have looked at many forms but the way the search engine algorithm works, I can't find my answers.. I've seen on many m4 stamps that they are magnum Tested ( two star ) but mine only has the one star.. did I mess up buying a new model? And should I try to find an old used m4 with more stamps. I've seen some with 4 stamps on receiver, and I only have 2, the CIP S and the single star over whatever the other symbol is. I will try to link a photo. Thanks for the help, I'm just confused at why some are magnum rated and other not.