Thanks to thedoormanmusic32 for the inspiration!
Weapon modification in Final Fantasy VII is interesting, to say the least. Normally in Final Fantasy, you just buy or find a weapon with elemental or status enhancements. But in Final Fantasy VII, you can upgrade your weapon to a stronger model as long as you obtain all the parts. Of course, the gunblade is a different weapon altogether. Not quite a sword, but not quite a gun. But as long as Squall acquires shells, screws, and blades, he can improve it. Yet curiously,
In Final Fantasy VIII, we are treated to a rendering of Squall’s Gunblade case, lying open and revealing its contents. Many people mock the fact that the case is shown to be housing six Bullets – speculated to be around .44 Magnum size/caliber – due to the fact that the Gunblade is never shown to have a barrel. My take on this: The rounds are purely for decorative purposes, much like the Griever motif hanging from the handle.
In my experience, whenever I have bought (or witnesed the purchase of) a Firearm or Sword, they usually come either entirely unpackaged, or in pretty plain packaging, usually cardboard boxes. The highly decorative case, and the recurrent Griever motif on the weapon itself, leads me to believe that the sword was custom made for Squall, as both the case and weapon bear a Lion Motif (Griever) that is widely considered in-universe to be unique to Squall. I doubt someone like Squall would scour every Blacksmith within Balamb and Balamb GARDEN just so he can happen to find a weapon covered in his own personal symbolism. It’s pretty easy go believe that SeeD candidates could be gifted with a Custom-Forged weapon upon reaching the highest level of “proficiency” in said weapon that the GARDEN can teach.
I suggest that the “cylinder”of Squall’s Gunblade simply serves as the housing for the vibration mechanism the Gunblade uses to amplify its impact. Pulling the trigger doesn’t cause any sort of internal combustion, but rather momentarily activates the mechanism, causing ultra-high frequency vibration to travel through the blade.
TL;DR The Gunblade works exactly as prescribed, the rounds in the case are purely decorative.
That’s an interesting theory. But the Gunblade does have a barrel and a place to load the bullet. It’s near the base on the sword, right in front of the cylinder. Of course, we’re never shown Squall loading or reloading his weapon. Irvine frequently reloads. Maybe it just looks cooler when Irvine does it? Or perhaps the bullets in Squall’s sword actually operate in a different way?
We know that in Final Fantasy VIII, you can purchase Pulse Ammo for Squall. These are bullets with “sealed energy”. So then bullets serve a function, and the chamber works. But for Gunblades:
The weapon’s debut appearance, the gunblade is the weapon of choice for Squall Leonhart and his rival, Seifer Almasy. It is a sword with a firing mechanism, such as a pistol (as with Seifer’s Hyperion), or revolver (as with Squall’s weapons), which serves as the blade’s hilt. Despite its name, it cannot be used as a gun, meaning it does not fire projectiles, and can therefore only be used in melee combat, making it more like a gun supplementing a sword than a blade supplementing a firearm, e.g. a bayonet on a rifle. The firing of the gunblade’s rounds induces a tremor in the blade causing it to deal additional damage to whatever it strikes.
In this sense, the bullets don’t fire, but they aren’t purely decorative. So how do they work? Think of them like a battery, or better yet a spark plug. Pulling the trigger sends a shock throughout the entire blade, which causes the round to explode. But this ultra-high frequency vibration is what causes an extra shock to enemies. So then yes, gunblades need ammunition. It’s just the ammunition doesn’t work the way we think it does.