[gurps] Rifles as melee weapons

[Captain Joy]

In a recent game, one of my players wanted use his phaser rifle to  
conk a bad guy on the head.  I told him that was fine, but he'd be  
rolling against a relevant melee weapon skill, not his Beam Weapons  
(Rifle) to do it.  Both my players disagree; they think it is part of  
their Beam Weapon (Rifle) skill.

The rules as written say you use Spear skill to use a fixed bayonet  
(B p208).  I'm sure I've read somewhere that using ranged weapons as  
melee weapons is fine (this is GURPS after all), but that you use  
whatever melee weapon skill is appropriate when you do so.   
Unfortunately, I don't remember where I read it.

Can anybody point me to the official ruling on this?
--
captainjoy at mac.com
"It's life, Captain, but not life as we know it." --Commander Spock