At last!!!! Thanks @Bandit LOAF and probably @ODVS and @Pedro and whomever else is working on the WC4 remake.Here's the internal gun data from the PC versions of WC3 and 4. WC4 uses the same stats for the shared guns and simly adds new versions where needed (at the end).
While it's tempting to say these are the 'real' stats, note that they don't actually inform us of too much. These are the values the game engine starts from but actual gameplay adds all sorts of modififers (hero bonus for the player, multiplyers depending on what texture you hit, modiiers based on difficulty, etc.)
Name: Ion Gun
Strength: 30
Speed: 1800
Lifetime: 2.500000
Refire Delay: 0.347656
Energy Use: 30
Name: Meson Gun
Strength: 35
Speed: 1800
Lifetime: 2.500000
Refire Delay: 0.398438
Energy Use: 16
Name: Neutron Gun
Strength: 52
Speed: 1400
Lifetime: 1.500000
Refire Delay: 0.398438
Energy Use: 30
Name: Particle Gun
Strength: 43
Speed: 2100
Lifetime: 2.000000
Refire Delay: 0.398438
Energy Use: 22
Name: Photon Gun
Strength: 32
Speed: 1800
Lifetime: 2.500000
Refire Delay: 0.449219
Energy Use: 30
Name: Plasma Gun
Strength: 67
Speed: 1200
Lifetime: 2.500000
Refire Delay: 0.500000
Energy Use: 44
Name: Reaper Gun
Strength: 35
Speed: 1800
Lifetime: 2.500000
Refire Delay: 0.226562
Energy Use: 35
Name: Laser
Strength: 18
Speed: 2000
Lifetime: 2.500000
Refire Delay: 0.250000
Energy Use: 10
Name: Tachyon Gun
Strength: 70
Speed: 1600
Lifetime: 2.000000
Refire Delay: 0.347656
Energy Use: 40
WC4
Name: Ion Gun (HEAVY)
Strength: 60
Speed: 1800
Lifetime: 2.500000
Refire Delay: 0.347656
Energy Use: 30
Name: Mass Driver
Strength: 45
Speed: 1000
Lifetime: 2.000000
Refire Delay: 0.296875
Energy Use: 12
Name: Mass Driver (HEAVY)
Strength: 60
Speed: 1200
Lifetime: 2.500000
Refire Delay: 0.449219
Energy Use: 30
Name: Photon Gun (HEAVY)
Strength: 64
Speed: 1200
Lifetime: 2.500000
Refire Delay: 0.449219
Energy Use: 30
Name: Tachyon Gun (LIGHT)
Strength: 50
Speed: 1600
Lifetime: 2.000000
Refire Delay: 0.347656
Energy Use: 40
Dissappointed by the light tachyon cannons! It uses the same energy as the standard! This needs to be fixed in the WC4 remake! The Mass Driver is OP! Change this too. No info on weapon ranges though?