"The United States Naval Surface Warfare Center Dahlgren Division demonstrated an 8 MJ rail gun firing 3.2 kg projectiles in October 2006 as a prototype of a 64 MJ weapon to be deployed aboard Navy warships. [ ... ] Such weapons are expected to be powerful enough to do a little more damage than a BGM-109 Tomahawk missile at a fraction of the projectile cost. [ ... ] Its expected performance is a muzzle velocity over 5,800 m/s, accurate enough to hit a 5 metre target over 200 nmi (370 km) away while firing at 10 shots per minute."
I'm sure that these hypothetical railgun projectiles have some method of in-flight correction, but we haven't forgotten how to do trigonometry since WWI. :)
http://en.wikipedia.org/wiki/Railgun
"The United States Naval Surface Warfare Center Dahlgren Division demonstrated an 8 MJ rail gun firing 3.2 kg projectiles in October 2006 as a prototype of a 64 MJ weapon to be deployed aboard Navy warships. [ ... ] Such weapons are expected to be powerful enough to do a little more damage than a BGM-109 Tomahawk missile at a fraction of the projectile cost. [ ... ] Its expected performance is a muzzle velocity over 5,800 m/s, accurate enough to hit a 5 metre target over 200 nmi (370 km) away while firing at 10 shots per minute."
I'm sure that these hypothetical railgun projectiles have some method of in-flight correction, but we haven't forgotten how to do trigonometry since WWI. :)