Rather surprised at the amount of thought that people put into this.
I always just eyeball weapon ratings.
I agree, particularly since the weapon and combat system is rather abstract, with Consequences as actual damage.
A 9mm (Weapon:2) has around five to six hundred pounds of force behind it
A .44 (Desert Eagle, Weapon: 3) has around 1,100 to 1,500 pounds of force behind it
A .500 S&W (mentioned above) has around 2,200 to 3,000 pounds of force behind it.
Gotta be honest, seems around Weapon: 4 to me.
EDIT: Huh, I've got different numbers, what is your source Fantazero?
Took a quick look at some of munitions books, specifically Ammo & Ballistics 3rd ed. and 4th ed. both by Bob Forker, and here is the info and my conclusions:
The .500 Smith & Wesson Special Magnum loading which has the highest foot-pounds (a measure of kinetic energy) at the muzzle is the Hornady 300-grain FTX (9249), with 2,868 foot-pounds at the muzzle
http://www.hornady.com/store/500-SW-300-gr-FTX-LEVERevolution/Now, a .308 Winchester, which is the same round as a 7.62mm NATO, also from Hornady, the 178-grain BTHP Superformance Match has at the muzzle 3,043 foot-pounds.
http://www.hornady.com/store/308-Win-178-gr-BTHP-Superformance-Match/Given that a battle rifle chambered in 7.62mm NATO, or a normal deer rifle chambered in .308 Winchester is per the Weapons chart considered Weapon:3, then an over-sized handgun (with examples given like a .50 AE Desert Eagle) should also be Weapon:3. Oddly enough, the chart already has that.
Therefore, I would really suggest people just stick with the chart. Unless or until the players start shooting, or getting shot at with significantly more potent weaponry like AGM-114 Hellfire II anti-tank guided missiles, or 120mm APFSDS tungsten KE penetrators from the cannon of a Leopard IIA6 or M1A2 Abrams main battle tank (MBT), then weapons with ratings between Weapon:1 and Weapon:3 are going to cover virtually everything a character could reasonably get their hands on. Weapon:4 could then be used for larger weapons, like if a character was able to get a mini-gun like the orange gorilla fired in Small Favor, or a 0.50 cal. Browning Machine Gun (BMG) or a 40mm grenade launcher, or just regular hand grenades.
On a side note, large calibre handguns are NOT usually used for hunting dangerous game like bears. What is usually used is a large calibre, high velocity rifle round like a .375 Holland & Holland Magnum. A large calibre handgun usually serves as a 'self-defense' weapon, so that if a hunter gets treed by a bear, or gets charged when the rifle isn't ready, the hunter can shoot the bear in shoulder to stop the bear. It is possible to kill a bear with something like a .500 S&W Special Magnum, but given the serious range/accuracy limitations a handgun that large has, deliberately attempting to hunt a bear with it could make the hunter eligible for a Darwin award, depending on whether the hunter has children of not.
-Cheers