The Ruger 10/22 carbine was introduced in 1964, and after 50 years and millions of carbines produced, is one of the most popular firearms ever made. They are inexpensive, reliable, and durable, and as accurate as can be expected for a basic rimfire. Every part of the 10/22 is available from multiple manufacturers, and it is possible to put together a version that is as accurate as any other semiautomatic rimfire made, though it is also possible to push the price into the thousands of dollars. However, it's also possible to add a bit of extra accuracy for just a few dollars in materials and a few hours' work.
The key to accuracy is consistency. Every shot must be the same; even the tiniest change in the process of getting the bullet out of the barrel can result in increased dispersion of shots. A match grade barrel, a highly rigid competition stock, and a highly polished, fully adjustable trigger will all make significant improvements, but at an equally significant cost. The improvements covered here will address the issues that can be addressed most cost effectively:
- Fitting of the action and barrel to the stock, so that nothing can shift under recoil
- Keeping the stock and action aligned, so that a receiver mounted scope will remain aligned with the barrel
- Managing the barrel vibrations, so the bullet exits at a consistent angle every time
- Minimizing trigger overtravel, to prevent the shooter from disturbing the rifle after the shot breaks
The tools needed are pretty simple:
- A Dremel or similar rotary tool, with a sanding drum attachment
- A drill and a set of bits capable of drilling into wood and aluminum
- Medium and fine sandpaper
- Razor or Exacto knife
- Screwdriver and Allen wrench set
- Tap for set screw (see below)
- Center punch (a nail will work)
And the materials:
- Putty epoxy
- Car wax
- Tung oil or varnish
- A set screw, 1/4" or smaller diameter, about 1/2" long
- Thread locker
While the process is fairly simple, this is work on a firearm, so it is not suitable for a novice. You should be familiar with the 10/22, and be able to completely disassemble and reassemble it with confidence. As usual when working on firearms, make sure there is NO AMMUNITION in the firearm or in the work area. In addition, this project requires the use of epoxy putty to produce castings of the firearm parts. If not done carefully, this process can glue your gun together, which can result in destruction of parts, so be very careful.
Step 1: Opening Up the Barrel Channel
The first operation is opening up the barrel channel, so that the wood doesn't touch the barrel. Check before you start to see if the channel is wide enough, by sliding a piece of medium thickness paper (a dollar bill works well) between the barrel and stock. It should slide easily all the way from the screw to the end of the stock. If it does not, then note where there is contact between the stock and barrel, so that the excess wood can be removed.
Once you have noted where to remove wood, remove the action from the stock. This must be done carefully to avoid damaging the stock:
- Remove the magazine, make sure the chamber is clear, and drop the hammer.
- Loosen the barrel band screw, and slide the barrel band off.
- Push the safety in. It won't go all the way to "safe", because the hammer is down. This is good, we want it to stop halfway so it won't damage the stock as it passes through.
- Loosen the screw holding in the front of the receiver. It should not come all the way out, just loosen it until it rattles around in the bushing.
- Lift the barrel up, letting the action rotate around the rear of the trigger guard.
- Once the barrel is up about 20 degrees, lift the action from the stock.
Lay the action in a safe place, on a towel or other cloth to keep it from getting scratched. Watch out for the two pins that hold the trigger group into the receiver, they can slip out when they're not held in place by the stock. If needed, use a bit of masking tape to hold them in place, so they don't get lost.
Once the action is removed, use the medium sandpaper to sand down the inside of the barrel channel. A wadded up cloth or paper towel makes a good sanding block, pushing the sandpaper into the channel with consistent pressure and letting you sand the tapered channel evenly. Stop frequently to put the action back into the stock, tighten up the action screw (leave the barrel band off) and check to make sure you can easily slide the dollar bill from the forend up to the action screw.
Once the barrel channel is opened up, we can use the putty epoxy to add to the stock, and allow contact between the barrel and stock only where we want contact to exist. After that, we will seal the newly exposed wood, to prevent it from absorbing moisture and warping.
Step 2: Expoxy Bedding the Barrel and Action
When bedding a bolt action rifle, generally the only point of contact with the stock is the area around the recoil lug and the back of the barrel. That is fine for a bolt action, where the barrel is screwed securely into the action, forming what is effectively a single unit. The 10/22, however, uses a slip-in barrel. This is a good thing, if you want to change the barrel, and is the reason so many custom barrels are available. The downside is that the barrel and action do not form a rigid unit, and so they can shift relative to each other. High end 10/22 clones address this by threading the barrel and screwing it into a threaded (usually steel) receiver. To keep things cheap and easy, we're going to use the stock to provide support. Another difference in the bedding has to do with the caliber. Often, .22 rimfires tend to perform better best when the barrel is supported by a pad near the tip of the forend. Pressure here would tend to damp the barrel vibrations with a wavelength of around double the barrel length. This is also a requirement for the 10/22, because the aluminum action is not strong enough to support the torque of a fully floating barrel.
We're going to bed the action at four spots; at each end of the receiver, at the breech of the barrel, and near the end of the forend. We want to have a moderately thick layer of epoxy, since thin layers will crack. To do that, we need to remove some wood at the points where we want a strong spot of epoxy. Using the drill or Dremel and a quarter inch bit, drill a shallow hole, about a quarter inch deep, at each corner of the rear of the action. Next, drill similar holes around the action screw. Those will support the action securely. For the barrel drill a couple of holes front to back at the rear of the barrel, and one where the barrel band sits. The areas around the action screw get the most holes, because the will bear the bulk of the pressure when the action is screwed into the stock. The rear of the action and the forend don't support much pressure, and thus need less epoxy to bear the load.
After the holes are drilled, apply several coats of the car wax to the action and barrel wherever it might come in contact with the epoxy--and don't forget the screw that holds the action in place, since we will be bedding around it as well. Apply the wax like you would to a car, adding a layer, letting it dry, and buffing it to a shine. The last layer you can leave un-buffed, just to make sure you have enough there to prevent the epoxy from sticking. Put a couple of thicknesses of masking tape on the barrel where it touches the very end of the forend, until it fits snugly in place, and do the same just in front of the rear barrel bedding spots. This will make sure than when you press the barrel into the epoxy, it will end up centered in the barrel channel. Do the same to the sides of the action, so it too will be centered in the stock.
Mix the putty epoxy according to the directions, and quickly put it into the holes in the stock, leaving it standing just a bit higher than the original level of the wood. Place the action into the stock and tighten the action screw moderately. Keep a bit of extra epoxy sitting out next to the gun, and check it after a few minutes to see if it has set up. Once it's difficult to mark with a finger nail, then pull the action from the stock and trim up any overflow with a razor knife. Let the epoxy sit for a couple of hours to make sure it's fully hard before reassembling.
Step 3: Seal the Stock
Sanding the barrel channel removed the finish from the inside of the stock, and that means that moisture could seep in from the air and cause the stock to swell or warp. To prevent that, use a thin varnish or wood oil such as tung oil to re-seal the expose wood. A brush-on finish works best, because it allows precise application, and we don't want to worry about overspray on the exterior of the stock or on the epoxy surfaces. Just brush a few coats of the finish into the wood, avoiding the points where the epoxy touches the metal; since those areas are a perfect fit, we don't want to add thickness and push the action further out than it should be.
Step 4: Opening Up the Barrel Band
The barrel band is intended to add some extra strength to the rifle, since without it, the only thing holding the barrel in the stock is a single screw. We don't however, want it touching the barrel. We could just leave it off, but that would also eliminate the extra strength it adds. The better way is to treat the band just like we treated the stock, and just remove the material that contacts the barrel.
For this, we'll use the Dremel with a large, fine sanding drum, close to the barrel size. Slip the band in place to see where it touches the barrel. Sand down those spots carefully, stopping frequently to check the fit. When you can easily slip the dollar bill under the band, start checking the spacing with the band tightened. When it slips easily in under a tightened band, then you're done. The band is aluminum, so it doesn't need to be finished, but if you'd like you can add a thin layer of paint or black marker to hide the shiny aluminum. If you use paint, make sure that the paint doesn't fill too much gap; if it does, you may need to remove a bit more metal to make room for the paint.
Step 5: Adding an Overtravel Stop
Overtravel is the distance the trigger travels between the release of the hammer or striker, and the point where it comes to rest. All firearms have some overtravel (too little and any dirt in the trigger group would result in the inability to pull the trigger back far enough to fire), but excessive overtravel is problematic. When the trigger breaks, there is a release of pressure on the trigger finger, causing the trigger to move backwards until it comes to a stop, and the trigger presses on the finger again. If this distance is large, then the amount of time that the force between trigger and finger are not balanced is large, and the gun can shift a significant amount. Minimizing overtravel doesn't exactly increase the accuracy of the gun, but it does increase the ability of the shooter to shoot it accurately. If you always shoot with the gun clamped in a vice, this is not an issue. If you ever shoot from an unsupported position, minimal overtravel can be vital.
There are two ways to add an external overtravel stop; you can put a screw in the back of the trigger guard to press against the trigger, or you can put a screw in the trigger to press against the trigger guard. Either will work on the 10/22, but adding the screw to the trigger means that if you mess up, you only have to replace the trigger, which is much less expensive than replacing the entire trigger group, which would be needed if you damaged the trigger guard.
The 10/22 trigger reset spring is located in the back of the trigger guard, and presses on a platform on the back of the trigger. To add an overtravel stop, we will need to remove the trigger from the trigger group, and move down to a spot just below that platform. Use a center punch to mark the spot, and drill through the trigger with the size bit recommended for the tap you are going to use. Tap the hole, and screw the set screw in from the front of the trigger, until it just protrudes out the rear.
To adjust the overtravel, reassemble the trigger group, and cock the hammer. Holding the group so that the trigger can start to fall, but not go all the way forward (which could damage the trigger group), see how far back the trigger needs to be pulled to drop the hammer. Screw the set screw in about that far, and adjust in or out as needed until the hammer falls just as the overtravel stop reaches the trigger guard. Screw it in about a quarter to half a turn more than the point at which it drops (so the sear will clear the hammer notch--too little overtravel will wear down the sear or hammer where they meet) and add a bit of thread locker.