Actually, revolvers do jam. The bullet can ease it's way out of the case, and lock up the action. This usually requires a significant amount of time to clear when it happens.
As for the Medusa, I'm not too fond of this gun. I've heard numerous reports of case splitting and the like when shooting some calibers in this gun. The gun will fire the caliber, but not well. Plus, accuracy tends to be reduced by making the gun capable of shooting a number of different calibers.
Plus, the gun isn't made anymore.

