But well, in GTA the cars are their own creation, their design is only slightly made on real cars (I saw some posts like "GTA cars in real life" on some websites) so it should be okay to make own guns making them only a bit similiar to a real ones and with different name, shouldn't it?
And about a song - it isn't related to some popular song title like creating game and naming it "hit me baby one more time". I just made a title and googled it - and I've found a song with exact title. So nothing related to lyrics and performers. Should it be okay?
And another example that it worked - there's a game Heaven and Hell realesed in 2003 and there's a song Heaven and Hell by C.C Catch made in '80s. There's also Black Sabbath album with such a name and one band uses that name. So should it be okay?