Abstract: A scope mounting system includes a one or two-piece base and a plurality of scope support assemblies. Mating portions of the base and scope support assemblies have parallel v-notches engaged with parallel flat lands to set the position of each support assembly relative to the sighting direction of a weapon to which the base is attached. The “flat land to v-notch” interengagement guarantees that the flat portions of all v-notches will engage one another to prevent movement along the weapon's sighting direction. Each scope support assembly clamps to the base in a way that prevents movement thereof in a two-dimensional plan perpendicular to the weapon's sighting direction.