Dragon Avatar+Gunblade=?

Does anyone know if it's possible to use one of Schism Industries' gunblades with one of Magician Productions' dragon avatars? Or their Ryu avatars?

Yeah, sure knock yourself out.

Really helpful answer Amy. *eyeroll*

To the OP: If you have an avatar made up of a lot of attachments (and a dragon sounds like it would), a gun would probably compete for one or more of the attachment points. So you wear the gun, and part of your hand falls off. This could just look weird and you might be able to live with it. If the attachment has scripts in it important to the functioning of the av, you'll obviously lose those too.
Finally, a non-human av's AO might make a gun (or blade, or... gun-blade) look wrong, point in the wrong direction. Or the weapon might have an AO in it that messes up your av's animations.

In general, any non-Human avatar that has prim hands/paws will have difficulty using any hand-held attachment, because you only have one attachment point for "Hand" on each arm, and only one for "Forearm" on each arm.

So for a simple example, if I am an anthropomorphic dog with prim paws on my hands, and I want to carry a sword in my right paw, then both the paw prims and the sword prims have to be modifiable, and preferably copyable, so I can make a merged paw and sword to attach to the single available right hand attachment point.

Any functional attachment like a gun or a sword that designed for Human use will also have issues working with non-Human avatars, because the animations for swinging the sword, firing the gun, or other actions will almost certainly conflict with the ones that make you walk on all fours, or that shape your body to fit into the inhuman shape and hide in the prims of the avatar attachments.

At best, expect it to be difficult. At worst, impossible or impractical. Contact the makers of both products directly, and see if there is some way to make them work properly together. Sometimes an attachment or weapon maker is willing to create a custom animation to resolve an issue with a specific avatar type that is otherwise unable to use their products.