Fixed mounts are all those mounts where detaching the scope from the rifle requires additional tools and cannot be done in the field. Fixed mounts are simple and offer the following advantages:
Being fixed also means that the user can use only one rifle scope on one rifle at a time and thus limits the usefulness of a single rifle. If you mount a wide-angle rifle scope for driven hunts on the rifle with a fixed mount, that means that it will be very hard to use this same rifle for anything else but for driven hunts. Hunting in low light for instance requires a different type of rifle scope.
In general there are three types of fixed mounts: