Why railguns could revive larger naval calibres

Could future naval guns be larger than about 155 mm?

Yes, especially if practical railguns return; electromagnetic naval-gun concepts have already explored calibres larger than six inches.

The roughly eight-inch scale explored for electromagnetic launch systems shows that large-calibre naval weapons are technically conceivable. The prediction remains conditional on railguns returning as workable fleet weapons, since current development may not produce an operational system.