Yeah, the round is 5.56 mm idiot. If its 556mm, you convert from millimetres to centimetres it's 55.6 cm, then to metres it would be 0.556 m, so again, that's not a rifle round, that's a long range artillery shell.
Calling yourself a giant is like calling yourself a 556mm round,you are large yes,but there will be an asshole who will correct you stating that it does not exist
Mate you're the hollow skulled bottom boy that's saying you'll kill someone with a artillery cannon from point blank range, has your ass even had a thought ever?
Oh no! Someone's saying I'm striving to be the best I can be! What ever shall I do?! Mate honestly just stfu, and for once in your life, actually do something right.