i haven't tried it out but i would assume its not awful, tho definitely not THE ideal moveset for offense or defense.
you would prolly want bite with hydro pump for quick energy build up. outrage is still good for offense though as it might be easier to dodge with but obviously has way less damage given with no STAB.
for defense, outrage is prolly the ideal charge move for gyarados. but bite is most definitely weaker than dragon tail.
so id say its a solid moveset, but not the best.
