Lining the .22-Caliber Rimfire Barrel

During the early 1900s, much of the .22-caliber rimfire ammunition available was quite corrosive. As a result, if the bore wasn’t thoroughly cleaned after a shooting session, the rifling soon suffered the consequences. Another potential problem results from someone trying to "shoot" a stuck bullet out of the barrel, causing a bulge just behind the parked bullet.

Relining a .22-caliber rifle or pistol barrel becomes a practical part of the repair plan when the price of a replacement barrel is prohibitive or anew one simply can’t be found. And keep in mind that a replacement barrel—if available—will most often need to be fitted to the action you are dealing with. Other things to consider are the brand of rifle you’re working on, and whether the cost is justified, especially if you plan on sending the barreled action off to someone else to have this work done.

The simplest solution, I feel, is to use the original barrel whenever possible, and relining is a project that can be done with relatively inexpensive equipment. Removing the Barrel Before you begin disassembly, make sure you are dealing with an empty chamber and magazine. Then strip down the firearm until you have just the barrel and action left.

With all the methods used to mount rimfire barrels to actions, a detailed description of removing the barrel from the action could take several pages, so I’ll keep this part very short. For this project, we’ll assume that the barrel is threaded into the receiver. The first thing you need to do is create reference marks to indicate the current barrel-to-action alignment. This could be a couple of small lines in the metal in an obscure area that will not be noticed after the gun is reassembled.

A couple of pieces of masking tape with pencil lines that

meet one another works also, but keep in mind that if one piece of tape walks off the job you’ll have a problem. I like to use two small lines scratched on the front face of the receiver and the bottom of the barrel where they meet in an area that isn’t seen after reassembly. To remove a threaded-on barrel, a strong, sturdy vise will be your best friend. For the .22-caliber rifles Ideal with that have barrels that are threaded on, I make barrel holding blocks and action wrenches from aluminum.

These blocks are simple affairs that I rough milled to shape and then form fit to the action and barrel contour using Acra Gel mixed with aluminum powder. The blocks are clamped in place around the action or barrel until the mixture has hardened. If you don’t have access to a milling machine, a rotary tool with a coarse burr-bit will also get the job done. The barrel blocks are then milled on each opposing face that fits around the barrel contour to remove about .030 to .040 inch of aluminum material.

The action wrench is also rough milled and then form fit with the same Acra Gel mix until it hardens on the front end of the receiver. When making the barrel blocks and receiver wrench, the important thing is to fit these as close to each other on the action and barrel as possible. Keep the barrel blocks at the very rear end of the barrel and the action wrench to the very front of the receiver to prevent twisting of the action during barrel removal.

Once you have the barrel removed from the receiver, study how the chamber mouth is configured. If you need to, photograph it as a reminder as to how it is shaped, blended, and ramped, since this shape will need to be replicated once the liner has been installed. Drilling the Barrel Once you have the barrel removed from the receiver, you’ll need to make an important measurement. This measurement is best done with a dummy .22 caliber round. Insert the dummy round into the chamber.

Use either a depth micrometer or the depth-reading stem from a caliper to measure from the back face of the dummy round to the shoulder on the barrel just ahead of the threads. Write down this measurement for reference later, as you’ll need to refer back to it when cutting the chamber. I don’t use my lathe to drill barrels for liners; I find that an electric hand drill works better for me.

I wouldn’t, however, try drilling with a wimpy 1/4-inch-capacity electric drill, and I’ve not had much luck with the cordless style either. And forget about the keyless-chuck variety also. The step-drill used to open up the bore needs to be held firmly in the drill chuck, and that means using a chuck key to tighten up the drill’s shank. I’ve even gone through the extra effort of milling flats on the drill shank, 120 degrees apart, so the chuck jaws achieve a firm purchase on the drill shank.

If you don’t hold this drill tightly in the chuck, you can expect the jaws to spin around on the drill shank. No cutting will take place when this happens, and you could possibly ruin the drill. The drills used to open up the bore to accept the barrel liner are 8 mm (around .315 inch) in diameter on the main cutting diameter, with a non-cutting pilot (.216 inch diameter) that guides by following the old rifling in the bore. These drills are available in two different lengths—9-1/2 inches and 15 inches long.

I use both of these lengths when drilling for the liner. The short drill is easier to start the job with, while the longer drill finishes up when I run out of reach with the short drill on rifle barrels. Secure the barrel firmly in your padded-jaw vise at around a 30-degree angle up from the floor. Because you’ll be using a whole lot of cutting oil, you want the oil to drain toward the cutting and into an empty coffee can or some such container.

It works best for me to use a handheld pump-oiler to squirt Do-Drill cutting oil into the bore liberally before cutting begins. Insert the pilot end of the drill into the bore and start the cutting process. A variable-speed drill works best for this cutting, and you will soon get the feel for how much speed you need to apply to get the drill cutting. Once the drill has gone an inch or so into the bore, stop the drill and back it out.

Clean the chips from the drill and bore, and refresh the bore with more cutting oil. Going an inch or so at a time,

For rifles, it’s best to use both. cut until you reach the limit of the length of the short drill, wipe out the chips, and then replenish the bore with more oil as you go. Reverse the barrel in your vise and begin the process from that end until you reach the cutting limit of the drill. Then use the longer drill to cut from both ends until the holes meet in the middle. Cleaning and Bonding We now should have an 8mm hole completely through the barrel.

The next step is cleaning the inside of the bore of any remaining chips and cutting oil that could prevent a solid bond for the epoxy that will hold the liner in place. A .30-caliber bore brush that has been wrapped with #0 steel wool and then dipped in acetone does a very good job of purging remnants of oil from the bore. I dip the brush in acetone and swab it out several times, and then run patches through the bore until they come out white.

I also wipe the outside diameter of the barrel liner down a couple of times with an acetone-soaked paper towel to remove any rust preventative that may be present. I use Acra-Weld for the bonding agent when installing these liners, and it hasn’t failed me yet. Mix up the Acra-Weld per the instructions on the box. I add a bit of black coloring agent to the epoxy to help mask the line between the barrel and liner at the muzzle after bluing.

An old playing card works well for a mixing pad and I use a popsicle stick as a spatula to mix and apply the epoxy. Smear a thin coat of the mixed epoxy along the barrel liner, striving

to get complete coverage along the length of the liner. Once you have the epoxy bonding agent on the liner, you can begin sliding the liner into the barrel. The end of the liner that has the groove in it is the end that should go toward the chamber end of the barrel. Rotate the liner as it is inserted to help the epoxy find its way into any tool marks created by the step-drill used to open the bore.

Use a paper towel to wipe up the buildup of extra Acra-Weld as it collects on the muzzle end of the barrel to avoid extra cleanup after it hardens. I create a small bead of the blackened Acra-Weld between the liner and the muzzle end of the barrel by pulling the liner out 1/16 inch or so, and then pushing it back into the barrel. This little bead will guarantee that you won’t have any gaps between the barrel and liner during the crowning process.

Crowning and Chambering For me, it’s standard practice to allow the Acra-Weld at least two days set-up time when relining a barrel. This way, I have a high confidence level that the epoxy is hard enough to work with. The next phase in the relining process involves crowning the muzzle. Carefully cut off the liner extending out the muzzle with a hacksaw, leaving 1/8 inch or so protruding from this end of the barrel.

Using a four-jaw chuck and a dial indicator, I set up the barrel in my lathe until I get the end of the liner protruding out the muzzle running within .001 inch or less. Lead shims are placed between the jaws and the barrel to prevent any scoring of the barrel finish. As you cut the crown for whichever style you prefer, you will end up with a black line between the liner and the barrel. This line is from the dyed Acra-Weld and will blend with the bluing.

Acra-Weld will hold up to any type of bluing you may perform on the metal, but it will not hold up to the soldering of sight ramps. If you need to attach sights by soldering, do this before the barrel liner is installed. For a single relining job, you could get by with just purchasing the finish reamer. The last, and most critical, step involved with relining a .22-caliber rimfire barrel is cutting the chamber. I use Manson chambering reamers, for no other reason than price.

For a relining job, you could probably get by with just using the finishing chamber reamer. I use the rougher first, and then the finisher, which means two reamers at double the cost. But I feel I get a better finish in the chamber as a result. The rougher is used to cut about 90 percent of the chamber, and then the finisher is employed to finish the chamber to final depth. A tap wrench works just fine to hold the reamer while cutting.

Use plenty of cutting oil, and remove the reamer after cutting 1/8 inch into the liner to brush chips out of the reamer flutes and chamber. Replenish the cutting oil and cut another 1/8 inch deep. Once the shoulder that will support the rim of the cartridge case begins to form, you’ll need to begin checking for the dimension between the dummy-cartridge face and the barrel shoulder that was recorded earlier. Stop cutting once this depth is reached.

A sharp edge will form around the area where the cartridge case nests. This sharp edge will need to be blended with the contours that surround the chamber mouth so that soft-nose bullets will transition into the chamber without hanging up. A 4-inch, half-round, No. 3 Swiss-pattern needle file works well to blend these areas and leave a smooth finish. Check for any remaining burrs or sharp edges at the chamber mouth and lightly file these away.

A cotton swab will quickly find these sharp edges by leaving fibers behind as it’s rubbed over the area. Conclusions All of the tooling, including the barrel liner, used to successfully install a barrel liner is available through our friends at Brownells. This is not a real difficult job to pull off in an uninterrupted afternoon. The job shown here was for a 24-inch rifle barrel, so the one-in-sixteen twist liner was used.

Now that we have .17-caliber, necked-down versions of the .22 Magnum available, along with the impending introduction of a .17-caliber on the .22-rimfire case, we also have .17-caliber barrel liners available. Chambering reamers are available as well. I can imagine that many of those old rimfire rifles chambered for obsolete .22-caliber rimfire ammo will soon be getting anew bore. ■