Without having to even buy tickets, the cast of the Avengers: Age of Ultron are all headed to the gun show...

There's no doubting that the stars of the new Avengers flick are in superhero shape, but would they be able to spot their own bulging biceps when confronted with them? That's what the folks at MTV wanted to know, and they brought the relevant material with them to put the stars through their paces. 

Reassuringly, they get most of them right, but we think most of them are pretty surprised by which one is Robert Downey Jr.'s. Spoiler alert: he's ripped.

They should have called this movie Avengers: Age of Swole-tron. Are we right, huh? Yeah?