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:
• Affordable price,
• High reliability,
• Small mass and simple structure,
• Easy installation (in most cases).
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:
Fixed mounts for dovetails and rails. Many rifles have dovetail grooves on top of the action to accommodate rings. Fixed mounts for Weaver and Picatinny rails also fit in this category.
Fixed mounts with base plates, where bases are attached to the rifle action and rings are attached to these bases.
Fixed mounts for original rifle mounting solutions, example being Blaser, Sauer, Mauser M03 and Merkel, where the fixed mount is incorporated into the gun itself.