Here are some examples of death rays and similarly dangerous weapons from the published modules and sourcebooks.

Pre-Emptive Strike
Vendetta uses Special Weapon: Death Ray Pistol: 174 inch range, inflicts 1d8 damage, plus Death Touch. No damage to non-living matter, in which case it attacks as a Paralysis Ray. 21 charges. Pistol is only usable by Vendetta as the butt is modified to recognize the holder of the pistol. If used by anyone else the pistol will explode, doing 1d4 points of damage for each remaining charge with a blast radius of 3 inches and a Hit Mod. of +3.

Tympanus carries Special Weapon: Multi-function ray pistol, 20 inch range 21 charges
(a) Improved Disintegrator does 1d20 damage, may be set for any particular non-living material, sparing all others.
(b) Paralysis Ray.
(c) Overload. Blast radius = 8 inches, +5 to hit, Damage = 1d20 + remaining charges. Weapon itself will be totally disintegrated by the blast, 7 phase countdown to overload blast.


Secret in the Swamp
Psi-Prime uses a Chemical Power Device: Dehydration Gun: Five charges. Range = 24 inches. A hit causes Devitalization damage of 4d10. It will have the additional effect of Death Touch attacks on characters with Water Breathing B powers.


Most Wanted Vol 3
Kiloton carries this Special Weapon: Huge Laser made of 40,000 lbs. of collapsium (SR = 20): +4 to hit, +3d10 damage. Range = 100 inches. As a club the laster is +2 to hit, HTH +4d10 damage.