[SOLVED] What is the most effecient way to move a character's head up and down?

I had all sorts of lag issues with my guns and I worked so hard to optimize them as much as possible. No matter what I did, something was making the activity rise over 8% when you looked up and down quickly while zoomed in. I finally found it was a method I've been using for a long time now. Moving your arms up and down by simply welding them to the head and moving the head up and down. I tried this:

RunService:BindToRenderStep(Tool.Name.."FPS", Enum.RenderPriority.Character.Value+1, function()
	Neck.C0 = CF()
	Neck.C1 = CF(0, 1.5, 0) * CFAng(MASIN((mouse.Hit.p - mouse.Origin.p).unit.y), 0, 0)
end)

Well, this sorta worked. I'd prefer to keep activity below 4%. Now the activity is 6-7%.

Do any of you guys know any better ways to make the character's head look toward the mouse?

I solved my own question!

What I did was I moved that code to a separate script from the gun. Somehow, binding RenderStepped performs better than Stepped. Here's my final code in a separate LocalScript:

wait(0.25)
Player = game.Players.LocalPlayer
Character = Player.Character
Neck = Character.Torso.Neck
Camera = workspace.CurrentCamera
RunService = game:GetService("RunService")
Tool = script.Parent

Tool.Equipped:connect(function(mouse)
	Turn = RunService.RenderStepped:connect(function()
		mouse.TargetFilter = workspace
		Neck.C1 = CFrame.new()
		Neck.C0 = CFrame.new(0, 1.5, 0) * CFrame.Angles(math.asin((mouse.Hit.p - mouse.Origin.p).unit.y), 0, 0)
	end)
end)

Tool.Unequipped:connect(function()
	Turn:disconnect()
end)

That script runs idling at exactly 2%. When you move your head up and down wildly, it actually gets REDUCED to a little over 1%. Found that extremely weird, but it works.