How to properly predict bullets?

[Ylsid]

A while ago I talked about a turret thing and with some advice, got it to call on both the client and server when you're firing it, opening the doors for prediction.
However I'm encountering a problem: the bullets are firing twice. Once on the server, once on the client. If I call it only on the client then it does no damage and the effect only shows up for the shooter, but if I only call it on the server no prediction.
Here's the shooty code I'm calling in the Think while ENT.Firing=true

[lua]

function ENT:DoShot()

if self.LastShot+self.ShotInterval<CurTime() then
if CLIENT then

local effectPosAng=self:GetAttachment(self.MuzzleAttachment)
local effectdata = EffectData()
effectdata:SetStart( effectPosAng.Pos)
effectdata:SetOrigin( effectPosAng.Pos )
effectdata:SetAngles(effectPosAng.Ang)
effectdata:SetEntity(self)
effectdata:SetScale( 1 )
util.Effect( "MuzzleEffect", effectdata )

elseif SERVER then
self:EmitSound(self.ShotSound,50,100)

end

if IsValid(self.shootPos) then --This is an entity to simulate where the bullets come from

self.shootPos:FireBullets({
Num=1,
Src=self.shootPos:GetPos()+self.shootPos:GetAngles():Forward()*10,
Dir=self.shootPos:GetAngles():Forward()*1,
Spread=Vector(0.02,0.02,0),
Tracer=0,
Force=2,
Damage=10,
Entity=self.Shooter,
Callback=function(attacker,trace,dmginfo)
if CLIENT then --This is only called on the shooter's client however, the other clients can't detect that they're shooting (ENT.Firing=false) therefore this is not called

local tracerEffect=EffectData()
tracerEffect:SetStart(self.shootPos:GetPos())
tracerEffect:SetOrigin(trace.HitPos)
tracerEffect:SetScale(6000)
util.Effect("AR2Tracer",tracerEffect)
end

end
})

end

self.LastShot=CurTime()
end

end[/lua]

If anyone at all could assist here I'd be very grateful. I don't really understand how prediction works.

[Walrus Viking]

You should try making 'Firing' a networked boolean or something, and only fire bullets [b]serverside[/b].

also for delaying the shots, you can do this instead (Which makes it easier)

[lua]local NextShot = CurTime();
local Delay = 0.25; -- 250 milliseconds

if ( CurTime() >= NextShot ) then
-- Do shit here
NextShot = CurTime() + Delay;
end
[/lua]

[Ylsid]

[QUOTE=Walrus Viking;41049752]You should try making 'Firing' a networked boolean or something, and only fire bullets [b]serverside[/b].

also for delaying the shots, you can do this instead (Which makes it easier)

[lua]local NextShot = CurTime()
local Delay = 0.25 -- 250 milliseconds

if ( CurTime() >= NextShot ) then
-- Do shit here
NextShot = CurTime() + Delay
end
[/lua][/QUOTE]

that won't predict though