October 3, 2012

Thoughts on Accurizing the M1 Garand

Volumes have been written on accurizing and sporterizing the Garand, but everything starts with a careful and thorough initial disassembly and inspection.

This rifle needs little introduction, but a gas-operated semi-automatic military rifle is always a bit more challenging to work with than most sporting rifles. The Garand uses an en bloc clip rather than a box magazine, and is very reliable with proper loads. But like many rifles, the Garand was produced quickly on a wartime footing, and variations are to be expected in the original WW II production. The tolerances are designed to allow mass production more than precise accuracy. Just the same, the Garand is a wonderful rifle and a good shooter, and deserves the respect it’s earned as part of our American heritage.

M1 Garand

When you work on a customer’s rifle, you’ll always want to be certain from the outset that you understand his needs and how he intends to use the rifle. You should be aware—or your customer should be—that certain modifications can disqualify the rifle for basic rifle matches under DCM rules. In the case of the rifle I worked with for this report, the owner simply wanted a more accurate rifle for casual shooting. He was also anxious to find out if he’d gotten a good buy on what he originally thought of as a “parts gun.” As it turned out, the modest price he paid had delivered a good rifle.

The primary variations in wartime production are generally in the gas tube and the wooden parts. A buyer can’t do much picking and choosing on these used service rifles, but the 1950s production was standardized and seems the choice when available. The rifle illustrated here features Beretta parts, except for an American-made cast receiver. The Garand was adopted by the Italian armed services after World War II, and Beretta production has an excellent reputation.

M1 Garand

As the trigger group is guided out, the pins that hold the hammer and trigger assembly in place become visible.

The initial inspection should turn up any problems with the rifle that need to be addressed. Even well-worn rifle bores are usually acceptable for casual shooting, but a replacement barrel may be needed for match use. I suggest a shooter get some experience with his rifle before deciding on expensive modifications.

The Century rifle used here arrived relatively free of preservatives. Department of Civilian Marksmanship rifles will often be coated with a thick application of cosmoline. Regardless of how it arrives, the rifle must be disassembled, cleaned, and inspected.

Basic Disassembly and Testing
To disassemble the Garand, the trigger guard is lifted up and to the rear. This rifle was very tight, and I used a wooden dowel for leverage to move the trigger guard. The trigger group can be removed at this point. Then carefully tip the stock up and remove the barrel and receiver. The barrel and receiver pull out in one piece along with the hand guard. Old lubricant and powder ash sometimes forms a type of varnish that can “glue” the rifle together and require a bit of effort to break. As the rifle is field stripped, I check the stock for cracks and the moving parts for wear.

If the rifle checks out okay with no obvious aberrations, I reassemble and test fire it. The Garand isn’t necessarily going to like any old .30-06 soft-point hunting ammunition you have left over around the shop. The rifle does feed soft points, but the cycle of the rifle is tailored toward a specific pressure curve. Handloads with slow-burning powder may not be appropriate. I always use Federal American Eagle .30-06 for testing. This is high-quality ball ammunition that always gives good results in the Garand. The rifle should be lightly lubricated prior to firing. Be certain you use quality en bloc clips, and never attempt to load the Garand with a single round. This can produce slam fires, which I’ll discuss later. If the rifle functions properly, proceed to the next step.

M1 Garand

Two large pins hold the trigger and hammer assembly. The trigger pin may require some effort to remove, but the hammer pin is often quite easy to push out.

Detailed Inspection And Modification
After the firing test, disassemble the rifle again. The operating rod should be tested for proper drop into position. The cutout holding the rod pretty much defines the proper travel for the operating rod. More detailed disassembly begins by unhooking the operating rod by moving the spring and follower rod towards the muzzle. Without pressure on the operating rod, you can once again move it, looking for pressure and binding. Many long-time Garand shooters have told me the operating rod is the source of most malfunctions. A bent rod is often the result of too-hot ammunition, although rough handling can also be to blame. At the same time you’re testing the op rod, be certain the bolt locks into place smoothly. There are occasional rubbing problems with surplus guns. Careful sanding can relieve the travel area of the operating rod. A dirty gas cylinder also produces problems. Cleaning it will usually cure sticky operation.

Next, take a look at the receiver. Turn it upside down and press out the follower pin that holds the bullet guide. This is not a roll pin, but a straight pin with a head like a nail. With the muzzle side of the receiver to your right, the head of the pin is oriented left. Once the pin is tapped out, all the receiver parts are easily pulled free.

There is a clearance cut for the operating rod in the back rear of the receiver. Apply pressure to the rod until it moves into place just over this clearance cut. Little effort is usually required to pull the rod free. Now you can inspect the bolt and bolt face. It is possible the bolt face may be pitted or damaged from firing.

While the rifle illustrated here features a new receiver, it’s still a “parts gun” requiring close scrutiny. Again, the rifle passed this test. An indent resembling a cartridge head on the bolt face is a sure sign that too powerful loads have been used. A pitted or rough bolt face can be carefully polished to aid feed reliability and function. If the rifle bolt is dirty with varnished oil and powder, a thorough cleaning is needed.

Now, let me offer a few words on the proper use of the Garand’s en bloc clip. This is not gunsmithing, per se, but anyone who works with or shoots the M1 needs to know how to avoid the dreaded “M1 thumb.” The en bloc clip is loaded with eight cartridges. The cartridges must be loaded so that the cartridge case head is square against the rear of the clip. (There is no front or rear; you pick the rear of the clip when you load it.) The cartridges are slightly staggered. The bolt is locked to the rear and the clip is pressed in with the thumb until the clip locks in place. Then the thumb is quickly removed and the bolt pressed to the rear in a sweeping movement. If you’re not quick, your thumb can be slammed forward, producing the M1 thumb. When the cartridges are fired, the en bloc clip is ejected. If you want to unload the rifle prior to firing the complete load, a lever on the left side of the receiver is the clip release. This will eject the clip and any round in the chamber when the bolt is pulled to the rear.

M1 Garand

The operating-rod lug rotates the bolt out of lockup. Examine the lug carefully; it’s sometimes found to be broken or cracked.

Now, back to the receiver and disassembly: To remove the clip latch, you’ll need to tap the long pin at the rear of the receiver. Tap it forward. There is a spring involved that can be lost if you’re careless with this step.

It is not necessary to remove the sights unless you’re going to replace them. However, sometimes the sights are stuck or in need of cleaning. It is amazing what military service can do to a rifle. The adjustment screw on the left side of the rifle sight is loosened. This allows loosening of the slotted nut on the right sight. All parts can then be lifted away, and the sight cover pushed off. The pinion and nut that control adjustment should be sharp and clear with well-defined detents.

Moving to the trigger group, I recommend giving it a careful study if you’re not already familiar with it. This is a military two-stage trigger designed for safety and longevity. There are two areas of concern. One pin holds the hammer assembly and the other holds the sear and trigger group. The hammer must be released prior to disassembly. It can’t remain cocked, as great pressure is exerted on the pins when the hammer is in the cocked position. On the left side of the trigger group, you’ll see the trigger pin. If the pin is at all difficult to drift out, you’ll want to move the trigger group forward and compress the trigger spring. With the trigger pin removed, the trigger, trigger spring, and related parts can be lifted out. The hammer pin is never difficult to remove, in my experience. At this point all parts should be checked for wear or cracks, which indicate the need for replacement.

M1 Garand

Garands on the surplus market are often of wartime manufacture, but the trigger groups and magazines are usually well-fitted to the stocks nonetheless. Parts of this rifle were made by Beretta.

Glass bedding the Garand is more difficult to do than with most bolt-action rifles, but is well worth the effort if superior accuracy is the goal. But, again, be certain your modifications don’t disqualify the rifle from certain types of matches. The Century rifle used for this article was quite accurate as received, giving us some incentive to try to produce an even more accurate rifle. The rifle’s bedding is complicated by the need to address the handguard and gas cylinder. I learned through some research that the bedding compound needs to be anchored in bedding grooves. While various publications of the DCM and NRA outline the anchor points, by laying the receiver in the stock and marking the meeting points between receiver and stock, you can judge your bedding points. At these points, grooves for the bedding can be made with a Dremel tool. A cut shaped like a horseshoe is engraved in the area below the rear of the receiver to aid in stock fit. I use a cut about 1/4-inch deep and perhaps 1/8-inch wide. This handles the rear of the receiver. Two grooves are inletted into the stock. One is cut for the clip release and the other is cut for the operating rod. The side cuts will also be 1/4 by 1/8, again watching out for the clip-release inlet.

The receiver bears attention as to fit in the lower stock. Don’t cut over the trigger channel, but the housing covering the magazine and the trigger-guard areas can receive anchoring cuts. When cutting the inletted portions, by comparing photographs in some NRA publications, I realized that this receiver is a bit beefier than some. I was told that the maker had experience with the Garand and beefed the receiver up where he had seen problems with the original Garand. Conventional wisdom tells us the bedding cuts on the rear of the stock are the main anchor points. We’re simply trying to ensure that the rifle returns to battery in exactly the same way time after time.

M1 Garand

The Garand rifle sights are good examples of battle sights even by today’s standards. Note the “PB” engraved above the adjustment turret. This stands for Pietro Beretta, the maker of Garand rifles for the Italian army.

Next, we must be certain every possible hole in the receiver is found and filled with clay. The recess for the clip latch and all slots must be filled. Remember to line the receiver and trigger housing with release agent. Don’t skimp with the clay in covering the working parts and don’t skimp on the release agent. The receiver lugs demand careful attention here.

I use AccuGlas, but your favorite bedding compound will be fine. Use enough to do the job and be certain you’ve filled the cutout slots and that there’s plenty in the interior recesses. I use a painter’s mixing paddle to help in “painting,” as I call it. I’ve placed a bolt-action straight into the wood, but with the Garand I find the best leverage is realized when the right side of the stock is up and secured in a vise, unless you have a helper and can make it a two-person job. As with any bedding job, press the receiver in straight and never pull the barreled action out. You must be familiar with the Garand to do this smoothly. Wait a few minutes and turn the rifle over and insert the trigger group, checking constantly for proper alignment.

After letting the compound cure overnight, you can remove the barreled receiver the next morning and trim up the bedding. I know from experience that tapping the barreled action away must be done carefully—mistakes can result in a ruined stock. After removing the action, clean the modeling clay and release agent from the action. Standard procedure calls for allowing the bedding to cure for at least a week before test firing.

Troubleshooting Problems
The two problems I’ve found to be most common with the Garand are short cycles and slam fires. I would much prefer to have to deal with short cycling rather than slam fires, but here are some thoughts on both problems. The Garand is reliable and durable because of a well-designed gas system. But the gas system is much like an automobile engine. When the pistol or cylinder become worn, you get blow-by, meaning that worn or corroded parts are letting gas slip by. The result is that not all of the gas is being used to operate the action, and problems in cycling are the result. Short cycling is simply the operating rod failing to move the bolt far enough to the rear to fully function the rifle. While polishing a problem cylinder can sometimes solve the problem, the best choice is to install a new gas cylinder. The guide lug on the operating rod is used to rotate the bolt out of battery. This lug can become peened or cracked and give problems. The lug can be ground off and a new one welded on, or the whole rod can be replaced. The grind-and-weld option is recommended only for those gunsmiths with the proper equipment and experience.

M1 Garand

This photo shows the turret adjustments from the top. The sight cover is in front of the sights, covering the spindles.

Slam fires occur when the rifle fires out of battery or fires when the bolt goes home on a chambered cartridge. The most common cause is poor ammunition. Handloads with high primers can produce slam fires as the bolt goes home. This is a two-fold problem, since the Garand has a floating firing pin. Often, if you remove an unfired cartridge from the Garand’s chamber, you’ll find the primer has a small dimple from the firing pin. It doesn’t seem to hurt anything, but you can imagine what would happen in the case of a handload with a high primer. As such, handloads for the Garand must be of the proper dimensions. Additionally some concern is voiced by competitive shooters regarding primer selection. The CCI #34 military specification primer is dictated by many for Garand use, as it features a harder primer than some and one that will endure the Garand’s floating pin.

Another concern is improper loading of the Garand. The Garand is designed to feed and strip a cartridge from the magazine. It is not intended to be single-loaded. When the bolt is allowed to slam forward on a chambered cartridge, much more force is exerted and this could give extra impetus to the firing pin, causing a slam fire, thus the importance of following the proper procedure when loading. This applies to the M14 and M16 as well. Even if a single round is to be tested, the round must be fed from the magazine. There are devices available similar to the Garand’s eight-round en bloc clip that allow firing a single cartridge, such as the “Sled.” There are also specialty en bloc clips with a two- or five-round capacity.

Another possible cause of slam fires in the Garand is a return spring that’s too heavy. If the return spring is too heavy, it returns the bolt forward too forcefully, and the firing pin is almost guaranteed to take a run forward. Still, operator error is the usual suspect in slam fires. The gunsmith must look for mechanical causes, but counseling the shooter will usually solve the problem.