damm, superman would definately win this battle, maybe by 50 different ways, but we have to also consider the hardness of true adamantium, i believe when they say adamantium is the hardest metal in all the comic universe, then nothing else is as hard as adamantium, that means that the altra hard metal can handel anything that is not adamantium, which means it can handle supaman's force field, the thing is, the metal will make superman feel pain but will little or no damage in his body physically, if they say that adamantium is the hardest metal, then were the f...k does all this f..ked up rumors that hulk and other mo' fo's bent adamantium. there was a comic that colossus even tried to bend a gate that is laced with adamantium in jail, the thickness of the metal is not even as thic as 1/8th of an inch in diameter, yet that thin, he could not even move/bend the metal with all his full strength.
Basically i believe that the metal as been degraded from its true properties, if a matal like adamantium is the hardest then it should have and i mean HAVE the true porperties. If kryptonite bullet can damage superman to a level, then why not adamantium bullets tiped with chizzle- points. it all depends on the writers though, if they support the theory of how hard adamantium is then i believe it is possible that wolverine can inflict some damage on superman, yet again his invernarability will keep him in pain but undamaged.