It was a mediocre action flick at best, hardly worth an R rating at all. There is nothing there to call "extreme". It's an R in name only. PG-13 would be just fine.
Yeah sure... Terry Crews blowing people to smithereens with his AA12 was PG-13. So was Gunnar blowing a pirate in half with a grenade launcher, SO PG-13... And Munroe getting shot 6 times before getting a knife through his back...and Sly cutting arms and heads off, and stabbing people through the next... Yup, I remember seeing this type of stuff in PG kiddie films!!
Don't be such a naive twat...
Plus the sequel has been confirmed as R, and critics describe it as an "orgy of exploding heads".