Gun don't aim at mouse, rather with strange offset

So, i’ve made the gun that aims to the mouse position, but it have strange offset and angle isn’t correct, does anyone know why?

	
	local CurrentCFrameR = RShoulder.C1
	local CurrentCFrameL = LShoulder.C1
	
	local OffsetR = CFrame.new(RightArm.Position):ToObjectSpace(Torso.CFrame)
	
	local X,Y,Z = CFrame.lookAt(Character.PrimaryPart.Position, Hit):ToObjectSpace(
		Character.PrimaryPart.CFrame):ToEulerAnglesXYZ()
	
	X += 0.1
	
	RShoulder.C1 = CFrame.new(-0.5, 0.5, 0) 
		* CFrame.Angles(0, math.pi / 2, math.clamp(X, -1, 1))
	LShoulder.C1 = CFrame.new(0.5, 0.5, 0) 
		* CFrame.Angles(0, -math.pi / 2, math.clamp(-X, -1, 1))
end)