You are totally fine... Im loading up several thousand .223/5.56 NATO and I can tell you from oersonal exoerience, you're A-OK!! It would be different if you bough loaded ammo and youre gun couldnt handle it but when youre reloading it, as long as you build up a load that you feep works good in your rifle and is accurate, you'll be all set. Thats the best part of reloading is you can control the load entirely!
Following is a link to a site that is very informative about the round in question and you will see for yourself. Also, if you dont have one yet, I would HIGHLY recommend a manual than information you receive from a forum, that could be dangerous if you take the wrong information as gospel.. just my $0.02 worth. Good Luck and Happy Reloading!!