Bows take longer to reload than any gun
Bullshit! Have you ever seen or used a flintlock pistol? Let's run through the process for loading a flintlock pistol.
First you have to pour in some black powder (gunpowder). Then you have to put in the shot, or a lead ball. Then you have to ram it all down with a small rod. Then you have to cock the striking mechanism.
Then you can aim, and pull the trigger.
I am
certain that in the time that it takes to reload a flintlock (or musket--same deal), a Viking can unload at least two to five arrows, depending on their skill.
And guns CAN be used by anyone, bows cannot.
As was mentioned earlier, this argument doesn't work. Vikings have to hunt for food, which means a large portion of them would know how to use a bow already. Perhaps not EVERYONE can use a bow, but I guarantee that the average Viking does.
That said,
Vikings > Pirates