Considering the freaking size of the Pandoran natives, I'd want a bigger bayo, though. Serrated. Actually, I wouldn't fight them with anything less than a chainsaw, but I suppose the meaning of the heavy caliber guns is not to let them get close to begin with.
Actually a serrated bayonet is less effective. It tends to get stuck in the target, so you have to wrestle with pulling it out. But yeah. I tried to make a Lancer style chain-bayonet for this, but it looked fugly.
If you work at it a bit, though, wouldn't they be more incapacitated after the fact? The horrid nature of serrated stab wounds is what I always thought was to blame for serrated edges on military knives and bayonets being banned over here. I've luckily not yet had any experience with using the damned thing on anyone, as it is, so I'm, uh, innocent of the grim reality, so to speak.