Re-jointing a Gun

By Delbert Whitman Jr.

There are certain occurrences that will elicit an instantaneous, visceral feeling of dread. We all have experienced these moments: the crackling noise and smell of ozone when you turn on your computer; the dripping sound coming from behind the bathroom wall . . . . I get that sort of feeling every time I pick up a fine old double gun, take off the forend, give the barrels and action a gentle side-to-side shake, and feel the telltale rattle and clunk of a gun that is “loose.”

All break-action guns eventually become loose and need to be repaired. If not remedied, the condition will have dire consequences for the gun. Although the problem is inevitable, the causes and remedies generally are not well understood. 

Laser welding has in many ways revolutionized fine-gun repair.

The term “loose” identifies the condition where the mechanisms that securely affix the barrels to the action have become worn and are no longer firmly holding the barrels against the breech face. The process of fixing a loose gun is referred to as “re-jointing.” When a shotgun is fired, the many thousands of pounds of pressure that are generated to accelerate the shot down the bore are also attempting to force the action open in several different directions. If there is any play, or movement, between the barrels and action during this high-pressure phase, a jarring/slamming effect can occur. This jarring/slamming effect will cause further wear of the locking mechanism at an exponential rate and eventually result in irreparable damage to the gun. A gun that is loose can have gotten that way because of two separate issues. The issues are not mutually exclusive, and a gun can suffer from both at the same time. 

The first issue is referred to as being “off face.” This means the hinge mechanism has become worn and there is now space between the barrels and the breech face of the action. For most side-by-side guns the hinge mechanism consists of a cylindrical pin called the “hinge pin” that runs perpendicularly through the front of the action. It fits correspondingly to a radiused mortis called the “hook” in the front lump of the barrels. When a gun is “jointed,” the barrels are fitted to the action so that they are in nearly 100-percent contact with the breech face. In effect, the hinge pin is pushing the barrels onto the breech face. The barrels also are fitted so there is a small amount of space between the barrel flats and the bar of the action called the “water table.” This space between the barrel flats and water table allows the barrels to move down and maintain their tight fit against the breech face as the hinge pin and hook wear on each other. When the downward movement of the barrels has eaten up all the space between the barrel flats and the water table, a gap forms between the barrels and breech face and the barrels are said to be off face.

Re-jointing a Gun
If a gun is “off face,” meaning there is space between the barrels and the breech face, the remedy is to increase the diameter of the hinge pin or add material to the hook.

If a gun is off face, the remedy is to add material to the hook and/or increase the diameter of the hinge pin. If the gun has a removable hinge pin, a larger-diameter hinge pin can be made and installed. That said, not all guns have removable hinge pins, and making, fitting and finishing a new hinge pin is terribly time consuming. The fix I more commonly employ is to add material to the hook, and then refit the hook to the hinge pin. I take advantage of modern technology and have a welding specialist laser weld metal directly onto the hook radius. Laser welding done by a skilled artisan can be truly amazing in its quality and accuracy. Material can be added with accuracy of a few thousands of an inch, the hardness of the filler material can be controlled and there is virtually no damage to surrounding material. Laser welding has in many ways revolutionized fine-gun repair. Once the new material is added to the hook, I hand fit the hook back onto the hinge pin. This is done with small files and scrapers, a blacking lamp and a large amount of time and patience. Once the hook is properly fitted, there still may be a small amount of fitting needed between the barrels and breech face. In summary: Having near 100-percent contact between the barrels and breech face is very important, as is leaving the right amount of space between the barrel flats and water table. 

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The second issue is referred to as being “out of take-up,” meaning that the locking mechanism has worn to the point that it no longer securely holds the barrels onto the action. There are numerous different locking mechanisms. The mechanism used in most side-by-side guns is a “bolt” morticed into the action. This bolt moves linearly front to back and engages cutouts, or “bites,” in the barrel lumps. The gun pictured uses the 1863 James Purdey patent “double underbite,” which uses the bolt to create mechanical pressure on the bites. This holds the barrels onto the breech face. The surface where the bolt and bites engage each other is slightly angled, so as they wear on each other the bolt further engages the bite. This is referred to as “take-up.” When the bolt is out of linear travel, it no longer can apply pressure on the bites. This is referred to as being out of take-up. A gun can be out of take-up but not off face. In essence the barrels and action still may be properly fit, but the bolt and/or bites have worn to the point that they no longer can hold the barrels firmly against the breech face. You should be able to feel the bolt engage the bites when exerting slight closing pressure on the toplever of the gun when it is closed. If the toplever snaps over with a clunk and can be pushed open with no feeling of resistance as the bolt disengages from the bites, the gun is definitely out of take-up.

Re-jointing a Gun
If a gun is “out of take-up,” meaning that the locking mechanism is no longer holding the barrels onto the action, material must be added to the engagement surfaces of the bolt, the bites or both.

To fix a gun that is out of take-up, material must be added to the engagement surfaces of the bolt, the bites or both. Again I typically do this via laser welding. In some rare cases an entirely new locking bolt is made. The bolt and bites are then set with the proper engagement angle and left with as much take-up travel as is safely possible. This is done by fitting the parts with files and abrasive stones in conjunction with marking compound or a blacking lamp. The feeling of a properly fit bolt and bites is unmistakable. The toplever will have a solid and firm feeling as it comes to a stop as the bolt fully engages the bites. Equally so, the toplever should move freely once the bolt has disengaged from the bites. 

A well-jointed gun has a certain feel. It’s hard to describe yet easy to recognize when you feel it. When you close the action, it has a solid, almost resonant feel—kind of like the barrels and action have become one monolith unit. 


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Shooting Sportsman Magazine, July/August 2020

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