30kg metal pole

Kamijou found himself clenching his teeth. The more-than-thirty-kilogram metal pole
fell toward him.
A moment later, however...
With a deafening, church bell–like noise, the sixth pole bounced to the side. As the
orange ray of light hit it, it split right in half, bounded along the ground, landed dozens
of meters away, and continued to slide. All the students nearby flinched away at first,
but within seconds they had returned to their frantic battle. Even then, the remnants of
the basket-pole clanged and clanked, bouncing across the ground.
Railgun.
One of the Level 5 abilities—to fire a bullet at three times the speed of sound.
As Kamijou Touma stumbled to his feet, he saw the Ace of Tokiwadai, bouncing a silver
coin on her thumb, sparks flying from her body: Misaka Mikoto.

- Toaru Majutsu no Index Volume 9, Chapter 3 Part 4