Why does the throw position always mess up?

So I'm trying to make a grenade toss that aims where the character's mouse location is, as long as that location isn't over 45 studs.

I have a problem with making it accurate. I think it's because the Velocity. But I'm not 100% sure can anyone tell me how I can make it accurate, or show me a script of how I should be doing it?

https://gyazo.com/651522d21b7e48256863470cfe78c8f9

This is what happens. The position that the grenade goes is totally off from the mouse.

game.ReplicatedStorage.Calls.ThermalD.OnServerEvent:connect(function(ForcePlayer,point)

    local ForceChar = ForcePlayer.Character
    local Players = game.Players:GetChildren()
    local anim = ForceChar.Humanoid:LoadAnimation(game.ServerStorage.ThermalDet)
    local Det = game.ServerStorage.Detonator:Clone()
    local DetRems = game.ServerStorage.DetRemains:Clone()


    if (point - ForceChar.HumanoidRootPart.Position).magnitude <= 45
        then

        anim:Play()
    Det.Parent = ForceChar
    Det.CFrame = ForceChar.LeftLowerArm.CFrame * CFrame.new(0,0,-1.7)
        Det.Velocity = point*3.5

    else

    return  

    end
        Det.Touched:connect(function()
            Det.Velocity = Vector3.new(0,0,0)
            Det.RotVelocity = Vector3.new(0,0,0)
            Det.Transparency = 1
            DetRems.Parent = game.Workspace
            DetRems.Position = Det.Position


            for i,Player in pairs(Players) do
        local iChair = Player.Character
        if iChair and iChair ~=ForceChar then
            if (Det.Position - iChair.HumanoidRootPart.Position).magnitude <= 16 then
                    spawn(function()


                local anim2 = iChair.Humanoid:LoadAnimation(game.ServerStorage.KnockBack)
                anim2:Play()
                    iChair.Humanoid.WalkSpeed = 0
                    iChair.Humanoid.Health = iChair.Humanoid.Health - 25
                    wait(2)
                    iChair.Humanoid.WalkSpeed = 16



                        end)

                    end

                end
            end
        end)

end)