Buying your own rail can be a really good way to learn how to grind. With your own rail, you can choose from the many options out there and get features that you prefer. You can choose between flat and round rails, the length of the rail you want; you can buy rails with adjustable height options and much more. Plus, you can take it to a nice quiet place and practice without all eyes on you while you bail trying a new grind, which is a nice luxury to have.