CNC Screw QSC

When using QSC quick-change spring guide in mechabox, QSC spring guide may be misaligned in some rare cases.This problem rarely occurs, especially in mechaboxes (e.g. AK) that do not have the spring mandrel bolted to the stock (such as M4s, etc.).

This locking screw eliminates the problem completely and allows for the trouble-free use of QSC quick-change spring mandrels.

The insurance screw is made from C45 material (12 050 steel) on a CNC machining center. Surface finish by briar plating (chemical blackening). There is an external thread M5 on the bolt. 

Tightening is done with a flat screwdriver or coin.