I haven't played this song since it was charted. Rusty! Big Gun is rather tricky, needs a few plays to get familiar. Slapped an popped this, my slapping sounded pathetic, I'm surprised I got past 80% I can't even be arsed to practice this. I also think any finger-style attempt, none slap attempt, should be void.
I was always told, any Bass path with slap and pop in it, is generally a 10. Which can probably stand for Can't Stop. If it was finger-style I'd count it as a 8. It's a hard one to grade and score as impossible to know who is genuinely playing it as intended. If I slap and popped this song I'd probably get 70% if I'm lucky :D