Raycast Gun Accuracy Help?

Hey, guys. So I read a little about the Roblox Wiki article about raycast weapons, and I made the following script that makes the gun shoot. It is working fine:

local tool = script.Parent
Player = tool.Parent.Parent
local user
fire = script.Parent.Handle.Fire
Shooting = false

tool.Equipped:connect(function(mouse)
    user = tool.Parent 
    mouse.Button1Down:connect(function()
		if tool.Ammo.Value > 0 then
			function shoot()
				Shooting = true
				local offset = {0.2,0.5,0,7}
				local numnum = offset[math.random(1, #offset)]
				
		        local ray = Ray.new(tool.Hole.CFrame.p, (mouse.Hit.p - tool.Hole.CFrame.p).unit*300)
		        local hit, position = game.Workspace:FindPartOnRay(ray, user)
		 
		        local humanoid = hit and hit.Parent and hit.Parent:FindFirstChild("Humanoid")
		        if humanoid then
		            humanoid:TakeDamage(20)
		        end
		 		
		        local distance = (position - tool.Hole.CFrame.p).magnitude
		        local rayPart = Instance.new("Part", user)
		        rayPart.Name          = "RayPart"
		        rayPart.BrickColor    = BrickColor.new("Bright yellow")
		        rayPart.Transparency  = 0
		        rayPart.Anchored      = true
		        rayPart.CanCollide    = false
		        rayPart.TopSurface    = Enum.SurfaceType.Smooth
		        rayPart.BottomSurface = Enum.SurfaceType.Smooth
		        rayPart.formFactor    = Enum.FormFactor.Custom
		        rayPart.Size          = Vector3.new(0.2, 0.2, distance)
		        rayPart.CFrame        = CFrame.new(position, tool.Hole.CFrame.p) * CFrame.new(0, 0, -distance/2)
				tool.Ammo.Value = tool.Ammo.Value - 1
				fire:Play()
				game.Debris:AddItem(rayPart, 0.001)
				wait(0.08)
			end
			repeat shoot() until not Shooting or tool.Ammo.Value <= 0
		end
    end)
	mouse.Button1Up:connect(function()
		Shooting = false
	end)
end)

What I want to do now is make the gun have some accuracy! To do this, I want to multiply the ray's CFrame by a small random number so that it will be slightly offseted from the player's mouse. Notice how in lines 13 + 14, I made a variable called numnum that randomly chooses a number out of the table called offset. NOW HERE'S THE PROBLEM!!: Where do I multiply this number to?... I'd gladly appreciate it if someone could help me solve this problem. Thank You! Oh! BTW, Hole - mentioned in line 16 - is where the ray originates from (the barrel of the gun). It is a part.