July 26, 2022
By Patrick Sweeney
A friend of mine who is a law enforcement trainer tells his students, "A sling is a holster for your rifle." A rifle without a sling is not always easy to carry, and it's virtually impossible when you're carrying anything else. The problem is, not all rifles leave the factory with sling-swivel studs. Luckily, installing your own is not that difficult.
To do the job right, you need the sling-swivel studs and the swivels, a power drill with bits of the correct size, a drilling guide and a thread tap (both available from B-Square), some masking tape and a bar of soap. The B-Square guide comes with the correct-size drill bits and facing and clearance cutters.
You'll also need either a padded vise large enough to hold your stock or a cleaning cradle. A bottle of Loctite will come in handy for the front stud. Luckily, everything you need except the soap is available from Brownells. I'll cover the traditional Uncle Mike's threaded-stud installation this time and later cover the installation of the QD (quick-detachable) flush swivels.
You may wonder why you need all this stuff? All you need is the drill, bits and the studs, right? After examining thousands of used rifles over the years, it was impossible to look at many without seeing crooked sling studs. They were off center, angled, tilted or some combination of odd orientations. Most of these, I'm sure, were a result of, "Hold the stock still, Bob. I'm going to drill straight in." Don't do it ugly, do it right.
We'll do the rear swivel first. Take the cleaning cradle and place it on a table where you can get a clear view of it. Don't worry about drilling just yet. Clamp the unloaded rifle upside down in the cradle, and position it so it is held exactly upside down. Leave the rifle assembled for now; you need it together to check alignment. Most of the time, when you clamp your rifle in the cradle it will shift and squirm and not be quite perfectly upright (or upside down). You want it as close as you can get it.
Take the B-Square drilling guide and position it on the bottom of the buttstock. The question always comes up, where to drill. If you drill too close to the toe of the stock, you risk chipping the wood and will have to repair the split-off section. If you drill too close to the grip cap, it can look goofy.
On some rifles or shotguns, putting the swivel in the grip-cap area is desired. If your rifle is a hunting rifle that gets hard use, or you're putting a sling on a police or defensive shotgun, the grip cap is an option. When slung muzzle down, the grip-cap location keeps the muzzle out of the mud, dirt, water and brush. It just looks a little strange.
On hunting rifles that are to look normal, I settled on locating the rear swivel three to three and a half inches up from the toe of the stock. Slide your guide to the desired location and place the drill bit in the guide.
Step back from the stock and look down its length. Is the drill bit pointing straight up from the belly of the stock? Adjust the guide until the bit is straight. Use the masking tape to hold the guide in place. Once taped, look again. Pull the rear swivel-stud drill out of the guide, lock it in the power drill, and drill your hole two inches into the wood. You needn't go deeper; the stud isn't more than an inch and a half on its threaded portion. Your guide hole is now straight up and down and on the centerline of the stock. Had you done it by hand, you may have gotten it straight, and maybe on the centerline, but not every time.
Pull out the drill bit, pull the tape off, and remove the guide. Install the facing cutter in your drill, and power it down the hole until you have just faced a circular shoulder for the stud to screw down to. Why the facing cutter? You need a solid seat to screw the stud down to. If you don't have the seat, when you screw down the stud it will crush the wood fibers on the high spots, and the crushed fibers will not always break evenly or cleanly. The cut seat gives you a clean installation.
Now take the wood tap and screw it into the hole, cutting the threads for your stud. Yes, you could just screw in the stud and force it to cut its way, but that is more work. It is also an invitation to chip the hole, or gouge the stock when you slip while forcing it. Worst of all, you could split the stock. Better to cut the threads and avoid the potential problems. Now screw in the stud. If the wood is particularly hard, use the soap as a lubricant to make the job easier.
When you get to the bottom, does the stud stop square? If it is only a partial turn away, torque it in until is it square. If the stud stops a half turn up, unscrew it and use the facing cutter again. Just kiss the shoulder, then reinstall the stud and check. Repeat until you can snug the stud square and tightly.
Once it is square, unscrew the stud and treat the shoulder with a stock finish. If your rifle has a particular finish, use it. Otherwise, a dab of linseed oil will seal the wood well enough. Once the oil dries, screw in the stud, tighten it and you're done.
On the fore-end, the customary use of the drill guide is inverted, from the inside of the barrel channel. I never liked doing it that way. As with the buttstock, if the stud was in the wrong place, I'd see it. Inside the barrel channel, the hole being off center a bit doesn't matter. So, as with the buttstock, pick a location. I again would go three inches or so from the fore-end tip and not through the checkering pattern. (Every rifle is a new exercise in location selection.)
Unlike the rear stud, which is made as a wood screw, the front stud is a machine screw with a nut. The forearm wood isn't thick enough to use a wood screw, so you'll be clamping the forearm between the stud head and the machine nut. To create clearance for the nut, you have to counterbore the barrel channel. Turn over the stock and clamp it in place. Install the front-stud counterbore cutter on the front swivel drill, and coming down into the barrel channel, counterbore the stud hole you just drilled. Counterbore just enough to keep the nut below the level of the barrel channel when installed.
The deeper you counterbore, the thinner you make the wood, so "just enough" is the operative phrase. But if the nut contacts the barrel, your accuracy may suffer, so it must be below flush. The nut is knurled, and when you press it into place it will stay in the hole. Seal the hole with a dab of linseed oil or stock finish before you press the nut in place.
Tighten the front stud into the nut, compressing the seat until the stud is square. Inspect the barrel channel. Does the stud stick up enough to contact the barrel? If so, count the extra threads, unscrew it and shorten it with a file or hacksaw. Once it is correctly fit, place a drop of Loctite on the threads and screw the front stud into place.
To install swivels on a Remington 742, 7400 or Model Four-series semi-auto, clamp the unloaded rifle in a padded vise. You don't have a lot of options and will have to clamp it by the receiver. Clamp hard enough to hold it in place but not so hard you squeeze the receiver. You can damage your rifle if you aren't careful. The sling-swivel package has a replacement for the forearm screw. You need to remove the old screw, and that can be difficult. It is a big screw, and most rifles that have seen a couple of hunting seasons or more will have the screw rusted in place.
Make sure your screwdriver is correctly fitted to the slot. Grind the screwdriver if you have to make sure, but it must be a close fit. You will be putting a lot of force into this, and if the screwdriver slips, you can mar the rifle or hurt yourself. If you find that you cannot generate enough torque with your hands, then use a crescent wrench on the screwdriver shaft. (That is why most big screwdrivers have square shafts, as a place to grab with a crescent wrench.) I never failed to remove a forearm screw this way. Even the ones that were a solid mass of crusty-red rust squeaked free when a 10- or 12-inch crescent wrench was applied.
If your rifle takes that much work, be sure to apply oil to the threads of the gas hanger before you screw the new swivel stud into place. (You could also clean it while you have it apart and save yourself some potential problems on a future hunting trip.) Pump rifles will have the front swivel attached to a band that clamps on the barrel. I always favored the two-piece bands, as they gave me more options as to location. The one-piece bands look cool, but they don't always lock in place in the best location. Yes, fitting an undersized one would correct that, but I, like many gunsmiths, had the simple economic problem that most of my customers weren't willing to spend much more than twice as much for installation as the swivel package cost. Custom-fitting a one-piece band would be much more expensive.
The trick with the barrelband is to make sure that the stud and swivel are far enough forward of the forearm that they won't interfere with the pump action of the rifle. If the swivel swings up during pumping and gets caught between forearm and stud, the rifle won't close and won't fire. I always degrease the stud parts and barrel and Loctite the stud assembly together and to the barrel.