Proper screw thread torque is an often overlooked and misused area of gun care. This is particularly true of the do-it-yourself gun owner with limited experience.
by Norman E. Johnson

Screw application can have an untoward effect on the mechanical function of a gun including accuracy and annoying bullet impact changes. Damaged screw heads detract significantly from the appearance and value of a firearm as well. If you are like most devoted riflemen and hunters you may be into at least some moderate gun work involving removing and tightening screws and mounting scopes. Scopes are often changed from one rifle to another in search of that perfect optical combination or a rifle action may be taken from its stock and replaced for one reason or another. Frequent use will leave screws vulnerable to damage. Most gunsmiths, as well as the experienced handyman, have at least a working knowledge of proper gunscrew application but for many there is much to understood about proper screw torque.