For anyone working extensively with precision firearms, encountering stripped or sheared screws is a recurring, albeit frustrating, reality. Despite employing high-quality fasteners, diligent preventative maintenance, and the correct tools, these issues inevitably surface. Successfully resolving them demands specific techniques and meticulous execution, often drawing on specialized tools and an understanding of the mechanics involved.
Before attempting any such work, it is paramount to recognize the inherent risks. Modifications to a firearm, especially those involving the action, should ideally be performed by a competent, licensed gunsmith. Incorrect procedures can lead to an unsafe firearm, potentially causing injury or death, and may void manufacturer warranties. The methods outlined here are for informational purposes, emphasizing the skill and precision required.
A common scenario involves a rifle, such as a Remington 700 Police action, presenting with two distinct types of damaged fasteners: a stripped screw and a sheared screw, each requiring a different approach. The necessary tools for such tasks are typically specialized, sourced from suppliers known for gunsmithing equipment.
A stripped screw, where the drive recess is compromised, typically presents the easier challenge. An initial attempt might involve using a slightly oversized Torx or Allen bit, carefully tapped into the damaged head to gain purchase. However, this method is not always successful and can sometimes exacerbate the damage, further stripping the head.
When the drive system fails, the next step involves drilling out the screw head. This method requires selecting a drill bit with a diameter just exceeding that of the screw's shank. With the action securely clamped in a vise, a cordless drill can be used to carefully cut through the head, effectively detaching it from the screw's body. If executed correctly, the screw head will separate, leaving the undamaged screw base and the shank still threaded into the action. The remaining screw shank can then often be removed simply by gripping it with a set of locking pliers and backing it out. This technique is reported to be consistently effective in these scenarios.
A sheared screw, broken off flush with the action's surface, poses a significantly more complex problem. Unlike a stripped screw, there is no material protruding to grip with pliers, and cutting a slot for a flathead screwdriver is often impossible if the break is perfectly flush.
In such cases, drilling out the screw body becomes the primary solution. While possible with a steady hand and a cordless drill, optimal results and minimized risk of further damage are achieved using a milling machine or a high-quality drill press. The rifle action is precisely secured in a V-block within the machine's vise, ensuring perfect alignment.
The drilling process begins with a spotting drill to accurately center the pilot hole on the broken screw. Following this, an undersized drill bit is used to drill through the screw body. Patience and precision are critical here; proceeding slowly and incrementally increasing the drill bit size are key. If the drilling remains perfectly centered, most of the screw material will be removed progressively. Should the drilling veer slightly off-center, one side of the screw might be cut away, allowing the remaining material to be collapsed inward and removed with a small punch. In some instances, after drilling, a tap may be required to clear any remaining thread material from the receiver, ensuring the threads are clean and ready for a new fastener.
Encountering damaged screws on a precision rifle is an inherent part of maintaining and building these specialized firearms. While frustrating, these issues are far from insurmountable. Depending on the specific damage and the tools at hand, a skilled individual can often resolve these problems. However, for complex situations, or if uncertainty arises, seeking the expertise of a competent gunsmith is always the most prudent course of action to safeguard both the firearm and the user.
