I have a crisp $100.00 bill for any one that will stand 21 feet away and take 4 rounds from my G42 to the torso.
Hell, you can even choose the ammo!
I hear comments like this all the time, and I think they totally miss the point. No one wants to get shot.
A better way to say it is probably "I'll give a crisp $100 to anyone who will allow me to shoot at them with my caliber of choice. It will begin 21 feet away and they're allowed to run at me, dodge, take cover, shoot back with the weapon of their choice, or close in and stab me or beat me as much as they'd like."
Because that's really what we're talking about. If you have to use a weapon at all you're not betting $100, you're betting your life.
The bad guy gets a vote, too. And the bad guy isn't necessarily driven by instinct like a bear; he has the benefit of knowing about and possibly owning a firearm, too. As stated earlier, killing the bad guy does no good if he lives long enough to return the favor.