I'm looking into a 597 to start shooting with, and I was initially going to over-do the Scope with a mind to not needing to replace it when I got a centrefire rifle later. However, I did note on the wiki page
Course, that's the Encyclopedia Anyone Can Edit talking, but it seems like one would want to use that weaver option if one were mounting a scope made for centrefire rifles.
The receiver has integral 11 mm dovetail mounts (sometimes called tip-off mounts). An optional weaver style scope base mounts to pre-drilled and tapped mount points.
The tip-off mounts are suitable only for small, light scopes for air rifle or rimfire use. Heavier scopes will tend to move on their mounts and thus loose zero. For these types of scope the weaver mounting system provides a more secure mount.
Course, that's the Encyclopedia Anyone Can Edit talking, but it seems like one would want to use that weaver option if one were mounting a scope made for centrefire rifles.