SWEP.ViewModelFOV Trouble.

I was trying to change the FOV in Leeroy base ( I am using because he send to me. ) But when i change the value of SWEP.ViewModelFOV = Nothing happens. i already put 90, 80, 75, 60, and nothing changes. I try everything, i talk with the leeroy oO but he is actually occupied. So i am wanting you guys help here.