Underlug staples were used on original guns! English, American, and European rifles, fowling guns, and shotguns were sometimes fitted with underlug staples.
Prompt service: Our gunsmith will install our underlug staple, for standard (halfstock size) wedge key, small (fullstock size) wedge key, or for a round steel dowel pin. Shop time typically requires 7 to 10 days for labor.
Underlug slot positions vary, depending on the style of rifle. Specify the number of lugs required, your choice of locations, or specify which of our pre-inlet stocks or plan drawings we should match, or allow our gunsmith to determine the best locations for your lugs. Most longrifles require three lugs.
Plain lugs are installed for pins. Slotted lugs may be installed for pin, as preferred by some gunmakers.
Slotted lugs are installed for keys. Specify which lug, or which key the lug must fit. Slotted lugs often require some fitting of the key to the slot, during final assembly.
Underlug slot positions vary, depending on the style of rifle. Specify your choice of locations, or specify the stock or plan pattern we should match, or allow our gunsmith to determine the best locations for lugs. Most longrifles require three or four lugs.
Do-it-yourself: Print this page of instructions, for later use:
Install your own underlug staple: this work is very easy, using a small #35 or 7/64" drill bit, a drill press, and our #TOOL-105-S staking tool.
Determine the location of your key or pin and transfer that mark to the bottom flat of your barrel. Design your own, copy an original, or refer to our plan drawings for guidance on pin or key locations. Originals vary widely.
Select the proper staple: for standard key, small key, or pin:
Our #UL-104-A large staple will accept a standard Hawken rifle size wedge key. Our #UL-104-B small staple will accept a small fullstock rifle size wedge key. Our #UL-104-C solid staple will accept a drilled hole for round pin, or swivel link. Our #UL-104-D small staple will accept a thin wedge key, or a round pin in the slot.
Determine hole depth: place your wedge key in the open staple, and measure the height of the leg that extends beyond the wedge key. For instance, our #UL-104-A lug has legs that extend about .073" above our #KEY-36-I wedge key. Thus, you will need to drill two (2) holes, on .500" centers, about .073" deep.
Measure barrel wall thickness: and compare it to your desired hole depth. If the barrel wall is not at least .050" thicker than the desire hole depth, do not use a staple. Instead, use an underlug in a shallow dovetail.
Layout your hole positions: which can be instantly achieved with our #TOOL-105-P double punch. Or, ink the bottom flat of your barrel. Mark the center of the key position. Scribe a centerline on the bottom flat. Prick punch two holes, .500" (one half inch exactly) center to center, on either side of your key position mark. Center punch these holes.
Drill your holes, but not too deep: measure the diameter of your lug staple's foot, and select a matching drill bit, probably #35 or 7/64". Set your drill press stop, to allow the drill point to penetrate the desired depth, no more. Compensate for the drill point, since the lug staple's foot will only enter the full diameter hole.
Recheck your work, to insure that you will not drill through.
Drill slowly and check depth often: recheck your work, to insure that you will not drill through.
Insert and stake one foot at a time: drive one foot into a hole, and stake the hole closed, using our #TOOL-105-S staking tool. The lug staple is very malleable, and can easily be bent or straightened. Secure one foot, then straighten and secure the other foot. It is more difficult to get both feet perfectly seated, than to finish one, then seat and stake the second foot.
You may wish to insert the wedge key into the staple, as a height guide, while staking the feet in place.
Inspect and straighten your lug staple: view it from the side, and from the top, and tap it into perfect alignment. Polish off any parting lines or burrs with a small Swiss pattern needle file, sold separately.
Underlugs staples are very secure: once staked in place, the underlug staple cannot be pulled out, without breaking the staple, since the barrel area immediately surrounding the staple becomes work hardened. Installation is very secure.
Repairs: failed underlug staples installations are rare. Obviously you must not drill into the bore. We don't recall ever repairing a failed underlug staple installation, but we can mill of the staple, and install a dovetail underlug in the same position, if required.
For safety: we require that the blind hole must leave .050" or more barrel wall to the bore or groove.
Not recommended for thin wall swamped barrels: we prefer to install underlugs in shallow dovetails, on swamped barrels, since the waist of the barrel is quite thin.
Our gunsmith will install your lug staples: promptly, perfectly centered, ready for use, at low cost. Specify locations, or allow us to choose the best positions. Labor options are not refundable.
