Outrage can do more damage, but, causes confusion, which'll damage you, plus, you are forced to use it for two or three rounds, and you can't switch out, which can be dangerous if someone switches to a Pokémon that is resistant to dragon, and or is super effective to dragons, or, if the Pokémon fighting you has super effective moves against Salamence, such as another dragon type move. Dragon Claw has no consequences, and has more PP, it does however do less damage. As for breaking swipe its not really worth it, seeing as how the only time you'll have more than one opponent in battle, is in a double battle, and you'll have another Pokémon to handle the other one, plus it has terrible damage compared to the other one. Overall, I'd suggest Dragon Claw, unless you're feeling lucky, then use Outrage.
