To Iceglow: I am aware of the Gunsword as a real life weapon, but I doubt the Gunblade is based on that. No offense.

The way the Gunblade works is that some energy is released within the blade whenever someone pulls the trigger (hence the use of the R1 button in the game), it has nothing to do with firing ammo or long-range battle - it is a fictional weapon in a fictional game, that relies on in game physiques. Nice idea though.

The Gunsword actually exists as a "Backup Weapon" for a character in the "Soul Series" begining in Soul Calibur 3, and you can actually use it as a long-range weapon (altough, the character's main weapon is basically a copy of the Soul Edge sword - so why he'd even need a back up weapon is beyond me...)