RemoveAmmo function on my SWEP isn't working

[SamJa]

My gun fires regardless of ammo, so I told it to stop firing after ten shots with a different variable. But to give the player some way to tell when they're no longer going to be able to shoot, I wanted to decrease their ammo by one every shot.

SWEP.Primary.ClipSize           = 10
SWEP.Primary.DefaultClip        = 10
SWEP.Primary.Automatic          = false
SWEP.Primary.Ammo                       = "AR2"

SWEP.Secondary.ClipSize         = 1
SWEP.Secondary.DefaultClip      = 1
SWEP.Secondary.Automatic        = false
SWEP.Secondary.Ammo                     = "AR2"

function SWEP:PrimaryAttack()
	self.Owner:RemoveAmmo(1, "AR2")			
end

In my actual code, there's more that happens in PrimaryAttack(), so I'm 100% sure that it's running. This produces no error message. To my knowledge, I should be able to see the ammo in the clip on the lower left on the screen decrease by 1, but that is not happening.

[Lilyxfce]

self:TakePrimaryAmmo()