Jose,
In your first example, the last axisX label(350,000) is automatically pushed inside the chart to ensure best fit, hence there will be some padding to the right of the chart. You can set labelAutoFit to false to override this default behavior which will remove any padding to the right, however the last label may get clipped.
Please check this JSFiddle for a working example.
—
Thangaraj Raman
Team CanvasJS