Come on boys you gotta choose your weapon
J-45 or AK-47
There's hell to pay at the gates of heaven
And the whole show it comes tumbling down
There's hell to pay at the gates of heaven
J-45 is a famous Gibson guitar used by John Lennon. Obviously AK-47 is the assault rifle so he is asking the ‘boys’ (presumably a reference to the young age of enlistment in world war one) to choose between violence or love/melody.
Hell To Pay At The Gates Of Heaven