I know you enough to know that neither you nor your friend coded this.
And "not working in multiplayer" is not exactly a useful information for this.
I tried it myself and it just seems to show a plain glock that does nothing when you fire along with a broken name and description.
If i'm not mistaken this is from the SWEP creator tool and he most likely didn't include all the required code from the actual post of the SWEP creator.
no reason why his friend couldn't make it at all
On topic, I bunged his code into an include to make this easier to use. Helps get rid of filling your SWEPs with junk.