Physics and magic are different stories... the logistics I refer to are this: there is no point in the arc of the swing of a sword in which the barrel would be pointing at the enemy. Physically speaking, if they block, the gun portion isn't focused anywhere near them, if you hit them, the gun portion still isn't focused anywhere near them because once you hit them, the force of the swing is stopped (swords don't actually travel through human bodies) at best you could lodge the sword in them, it would get stuck, and now you are stuck in the same redundancy as stabbing them (IE... you just lodged a huge chunk of metal into someone... shooting them at this point is a little unnecessary). and what's worse, once the sword is lodged in them, it most likely will have to be discarded or you have to spend time and effort dislodging it, during which time, the gun portion is useless.
In any of these situations I can't see a point where it wouldn't be better to have a sword and a gun, autonomously from each other.
Going back to the comment about magic though... In THIS world, neither one makes any sense. No one (i know of) can summon fire from nothing so the effort to do so is futile... but just as futile is the effort of trying to swing a projectile weapon like a melee weapon and still expect the projectile to have anything even remotely close to the desired effect.
In the world of the game though... the magic obviously happens so its not futile... but physics isn't altered (or if it is, there is no evidence of it) so the act of swinging a projectile weapon like a melee weapon and having it work is still a futile act. most likely you'd shoot wildly off the mark, or hit something else entirely(like the ground... or some poor shmuck off to the side.)
Batty's take makes the most sense but still the reaction time involved to pull a trigger midswing to discharge whatever effect in the blade is stretching the realm of the feasible.. though its much less of a leap than if it were a projectile.
The argument there is that I'm pretty sure there are cutscenes showing the barrel of the gunblades in ff8 are housed in the blades and shown to be projectiles... The one thing stopping me from looking for proof is that i think ff8 is a horrible game and have no intention of playing it again, ever.
Getting back to my original point though... Gunblades never made sense to me. Give me a gun, a sword, or a gun and a sword... don't try to put them together.
Edited, Sep 16th 2010 6:30pm by F3rth
FFXI: Ferth - Cerbereus Nee Hades Nee Leviathan.