Railgun promises and the difficulty of scaling up

How close are real railguns to the large, long-range weapons depicted in fiction?

Repeated promises invite scepticism, while a claimed working Japanese 3-inch railgun still leaves the problem of scaling up.

Alex Clarke recalls promises of working railguns at a defence conference in 1996. Similar assurances have continued through the following years. Japan is credited with a working 3-inch railgun. Expanding it to a larger weapon remains necessary before reaching the scale raised in the fictional comparison. No dependable arrival date is offered.