Knife Noobie needs a bit of help. Full-tang?

I would say definitely not... the "deadliest fighting knife" is probably a steak knife, plus I can think of many more fearsome knives than an M9 bayonet I mean there are massive bowies and dozens of types of medieval and Oriental daggers approaching the size of swords and they say a 7-inch Gerber is the "deadliest"?

 

If you can save up about $180, I think this knife would fit what you're wanting:

 

• 
  Support BladeForums!
  Paid memberships don't see ads!

If you look at the history of fighting you'll see that back when people fought each other with edged weapons they chose the longest piece of steel they could wield with speed and accuracy. Sometimes weapons were improvised from whatever was available, axes, pitchforks etc or they were purpose made. Some designs favored piercing over thrusting, or vice versa but neither style ever was superior as far as I know. The constant was that fighting knives were big. Those puny 9 + inch daggers were weapons of opportunity or backup weapons.

Probably the "deadliest knife" in the history of man is the one mounted on a long stick. The Spear. Or maybe it is the knife mounted on a winged shaft. The arrow.