[Secret Agent Man]

washers, slugs, bb’s, all are used in railguns.

[Utilizer]

For low-power devices, yes I can see that. For a device that can accelerate a projectile past the slingshot-speed range, some of the comments on the article page show that they are not really very practical, since they very quickly weld themselves to the rails instead of becoming useful projectiles.

[Fai Mao]

A galvanized finishing nail might work