Railway guns remained widespread in the Second World War

Did major powers use railway guns during the Second World War?

Yes; Britain, France, Germany, and Italy all used them, including British and German batteries firing across the Channel.

Britain, France, Germany, and Italy are identified as Second World War railway-gun operators. British and German weapons firing across the Channel illustrate their coastal role. British 12-inch weapons and extensive French holdings are also mentioned, though the place name given for the former is unclear. The British Army's use of the East Kent Light Railway supplies a more specific example of the railway connection. Some railway guns remained after the war.