Well, here's a quick run down so far with the second version.
M3 shotgun: Nice, though, due to it's power, it might need to use 2 shells.
Magnum: It's power level is over 9000! No, not really, but it's really powerful. Also, it fires chaingun bullets? They would either jam the barrel or explode, or not even fire...
M-60: Awesome, although it seems to be firing .50 cal round instead of it's standard 7.22 MM rounds. Or, did it fire 5.56? I don't know.
But um, after watching Rambo, I'd dare say it's a little more powerful then it should be. At least tone down on the gibbing.

Also, wow, the most powerful kick in the world.

No, really, while it's recommended to move while firing it, that's mostly so in real life, you don't have it break your hands/or fly out of them.
I suggest toning down the kick a little. Or something. It's powerful, but any weapon that makes you dizzy, is not a good weapon.
Smg/Dual SMG: Well, it's not that bad of a weapon, a little weakish.
"Quake 2 nailgun:": Um, this is the ugliest gun in history. No, really, Quake 2 didn't even have nailguns, so I really can't figure out the name
Razor Jack: Interesting, Seems to be a little powerful on it's alt-fire of flaming saw death, although not being able to kill an imp with it is very annoying if I don't hit it right. Same thing with sergeants. Suggestion, increase it's damage to M-60 status. Because let's face it, giant flying saw blades are going to kill you dead.
Pitchfork: Um, not so much new, as the default weapon for some odd reason. It's a bit weird to have to switch to the pistol when you start a map. Also, Berserk has no effect on it.
-2 points for consistency
All in all, not bad weapons, but balance is needed a little.
Also, what's this Quake 4 shotgun thing? Is that the weapon that replaces the shotgun, or is that another one?
Shotgun: Again, it's a showstopper, in a good way. I think it can damage tanks. I.E. it's a little powerful. I suggest making it a little more powerful than the normal shotgun, while keeping the M3 the better of the two.
Uh-oh! I found a big bug. If you have the Razor Jack, and pick up another one, the game crashes with an error message about an access violation.

This happens no matter how you spawn it. Using the Summon command, looking for it on a map. This is very bad. i'll go update the SVN and see if that works.
Nope, it's still bombing to desktop giving fatal error messages, etc. You'll really need to fix this.
Otherwise someone will have to constantly save their game just to make sure they don't lose too much progress when they crash immediately upon picking it up.