On a Forster jig, how can non-square based actions be fitted?

The correct choice centers on using a square from the top of the overarm as a means to fit non-square based actions into a Forster jig. This method is effective because it allows for precision in aligning the action with the jig, ensuring that it is properly seated despite the lack of a square base. Using a square provides a clear reference for leveling and aligning the action, which is crucial for maintaining accuracy during the fitting process.

Employing this technique is particularly advantageous because it helps make sure that the workpiece is perpendicular to the tool's movement, thereby enhancing the quality of the work being done. The square acts as a visual and physical guide, helping the user to achieve a proper fit without relying solely on the base's dimensions.

Other methods such as using a round alignment tool, adjusting the base height, or applying pressure from the sides may not provide the same level of accuracy and could lead to misalignment of the action within the jig. In contrast, the square method facilitates a straightforward approach to achieving the necessary alignment for effective use of the jig.