Would a rod fly faster than a ball in a cannon?

Above is our theoretical rod firing cannon, and below is a more typical cannon ball firing cannon. Each is loaded with a projectile of the same weight but different shapes, and both have the same amount of powder (though in different arrangements due to the differing projectiles)

My assessment is that the Rod will attain a higher velocity than the ball because of its superior aerodynamics to the ball, but my friend says that the ball will be able to better capture the force of the powder due to its wider explosive front.

So, what do the people with more physics knowledge think, ball or rod for a higher velocity?