Board Thread:Off Topic/@comment-25396609-20171116191014/@comment-25396609-20171203233847

Well, with how railguns work they tend to be single-shot to begin with. The basic mechanism is a cup/sled connected to a pair of rails (for which the gun is named). The projectile is loaded into the cup, an electrical current passes through the rails (thus magnetizing them) and the sled is pulled to the end of the rails by the current. The projectile speed is achieved largely thanks to the fact that electricity moves, well, really really fast.

For a proper railgun, your firing system is gonna need to include that basic system. From there, how powerful it is is really up to what exactly you're loading it with; the size and properties of the projectile.

Now, keep in mind whatever you put in it should be non-magnetic so as to avoid it simply being magnetized to the rails and failing to fire. No matter how you build it, the slow rate of fire is going to be your largest limitation in keeping it from being overpowered. It may be a practically guaranteed OHKO, but when your firing speed is only a handful of rounds a minute that only goes so far.