CFrame Linear Tweening is buggy?

        local distance = (TOOL.Handle.CFrame.p - Fposition).magnitude
        local TIME = distance/250
        local tweenInfo = TweenInfo.new(TIME)
        local tween = TweenService:Create(BULLET, tweenInfo, goal)
        tween:Play()

Using Velocity = Distance/Time v = d/t t = d/v Making v a constant this should make the projectile speed linear

When the Fposition is on a wall minor changes aren't noticeable, but when i click off into the sky the speed is noticeably faster and there are certain times at random that the projectile will travel at a much slower speed almost as in slow motion.