I'd honestly like to see a blanket "if no CC weapon, one handed firearms/smg's/melee weapons or natural Attack, then model may make unarmed CC attacks at -4 CC and ST DAM. Rifles, HMG's, two handed Ranged Combat weapons etc that have a CC stat make attacks at ST DAM. Bayonettes do full listed weapon damage plus any bonus's" that would cover everything nicely.
but that's just what i would do.
(and i've missplaced a very important phone number... -doh! so it might be a little bit before i get confirmation on a few issues)
-PFC joe