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My 7.62 NATO Garand Project
 
Article by Jamie Mangrum
 

Adobe PDF Downloadable Version of Article

 

Article Note

This article is not meant to be a granular, step-by-step set of instructions on how to assemble an M1 Garand from a parts kit. It is intended to display a high level overview that shows the complexity, the required skills, and specialty tools required to complete the job correctly.
 
I have been on a kick (or a binge) lately building my own mil-surp rifles. For several semi-auto rifles you can find receivers and parts kits that are very reasonable in price. The FAL is a great example but the legal technicalities are so difficult to wade through that I decided not to worry about the liability of building one. My fear is that I would build an FAL for an article, make a mistake and break some federal law, publish my mistake (felony) for all to see, and then become great friends with the ATF. The consequences would probably limit my future of writing about firearms other than articles starting out with:  "Poor me, I sure wish I had not committed a felony and I could still own a firearm to write about". 

So as a result, I decided to focus on building a rifle that so far has not been recognized as an imported, evil assault rifle. For a lot of us the M1 Garand is one of the most desirable of mil-surp rifles. We all grew up watching actors carry them in movies. Heck, even my GI Joe had two or three. I still have my GI Joe's little plastic M1 Garands on display in my office at work. Thank goodness no one has yet to feel threatened by them. 

Garand receivers run about $300+ and a parts kit and barrel goes for around $350. I have wanted a 7.62 NATO Garand for some time now. I especially wanted one after an article I wrote earlier: M1 Garand: 30-06 vs. 7.62 NATO. But, I wanted one that did not have a barrel insert, but actually had an honest to goodness 7.62x51 NATO chambered barrel. I have a few standard issue Garands, I just wanted something a little unique.

I purchased a reparkerized 1950s Springfield Armory receiver from my friend Don at River City Gun Exchange for $315. This project started back in November of 2004 when I went to the Big Reno Show. At that time I was making plans for articles in 2005 and decided I wanted to build a 7.62 NATO Garand. My other friend Randall who does all of the work in the following article said -"Pick out a good receiver and I will help you put it together."  So I dug through a big box of receivers until I found one that was just right. Then I acted like an ass! I took almost six months to pay for the receiver. Finally some time last month I went and decided to actually pay for the receiver that Don had been so graciously holding on to all of this time. I have to admit that I leave things at his store way too long. I am sure he would agree. Then finally guilt and good judgment will catch up with me and I go and pick what ever "it" is up and Don will say with a smile - "about damn time you picked it up!"

Note to self and others - don't ever take advantage of friends and especially friends that are FFL 01s!

Next, I had to find all of the other parts for my project. I thought about purchasing one part at a time and when I saw how much that endeavor would cost, that romantic notion flew right out the door. I did a search on the internet for M1 Garand kits and ended up at Sarco Inc's website. I chose what they call Kit "B", which consists of all parts (including stock parts) minus the receiver and barrel and the great thing is that everything has already been reparkerized. I then added a new .308 barrel. They offer four different parts kits:
KIT "A" M1 PARTS SET (M1RK-A) - All parts serviceable, with gas cylinder and operating rod and checked for serviceability. Remember these kits are individually gauged and checked, unlike others who sell them - as they run - out of the box. We replace any worn or broken parts as necessary. Barrel not included. $210.00
KIT "B" M1 PARTS SET REFINISHED (M1RK-B) - Similar to our "A" grade sets, but all parts have been refinished what matte military -type finish, with no polishing or grinding done to destroy the original appearance. Barrel not included. $234.50
KIT "C" 7.62 Nato M1 parts Set Refinished (M1RK-C) - Same quality parts as in our ?B: kit, except the barrel is a almost new take off, never fired. U.S. /G.I. Springfield Armory 1960's date marked barrel in 7.62mm NATO! Barrels were .30-06 G.I. barrels converted to 7.62mm NATO by Beretta for use in Italian issue M1 rifles. Conversion done by shortening barrel by 1/2 inch and rechambering. The operating rod has also been shortened to work with these barrels. You will have to shorten the rear handguard by 1/2 inch to fit the shorter barrel. This set comes with a new G.I. proper stock. $334.50
Kit D - Complete M1D parts less the receiver and scope. Includes proper barrel and scope mount, etc. Barrel & M1D Parts are current production as we sell else where in the ad. Parts will refinished as in Kit B above. As noted above all parts except scope & receiver - including mount & base. We also include a T-37 flash hider & leather cheek pad $595.00
NOTE ON BARRELS FOR OUR A&B KITS: Add one of our new production Citadel barrels for only $120.00
I received the parts kit from Sarco and everything was in good order.
Since we needed to headspace the rifle Randall started out by disassembling the bolt so only the bolt body would be used minus the extractor and firing pin. Let me say that every time I go to Randall's house I am either on the verge of dying with some sort of strange illness or like this time I had inadvertently eaten brown catsup. Brown (catsup gone bad) catsup is not really something you should ingest and when I realized my mistake I rapidly spit it out and spent the rest of the day fretting that at any moment I might die of ptomaine poisoning. I did not. Well, not yet.
Tool Name Price
M1/M14 Bolt Disassembly Tool Part # 080-818-000

$59.90

Next Randall hand threaded the barrel onto the receiver. He found, as he expected, that he could not turn the barrel easily to its final position. As a result he placed the barrel on the lathe and took a miniscule amount of material off of the face of the barrel where it would mate with the receiver. This is much easier than trying to wrench the barrel onto the receiver and will not damage the barrel or receiver if done correctly.
He then wrapped tape around the receiver to protect the finish from the Garand receiver wrench. This is a lot easier than marring your finish and having to reparkerize afterwards. When installing a barrel on a receiver it is common practice to use what are referred to as barrel blocks that lock onto the barrel. Then the barrel blocks are placed in a very large stationary vice as shown in figure 5. Note that Randal also placed tape around the barrel where the barrel blocks would clamp down.
Tool Name Price
Block, Garand Barrel

$45.00

Wrench, Garand Receiver

$125.00

As you probably guessed, the tape prevents the finish from being marred and gives the blocks something to grip onto. Then using a very long and heavy duty driver you rotate the receiver, threading it onto the barrel.
It is very important to turn only a small amount at a time and then check the alignment. This way you have less chance of over turning the barrel.  

The blocks pictured in figure 7 are called barrel/receiver timing gauges, sold by Brownell's. They work on M1 Garands and M14/M1A's.  They clamp on to the rear of receiver and gas cylinder or flash hider.

Installing and Alignment of an M1 Garand Barrel

Without using undue force, screw barrel on receiver by hand until it fits tightly. The receiver should be approximately 15 degrees out of its correct position on barrel to insure a tight fit when final draw is made in the carrel and receiver assembly fixture. Clamp the group in the barrel and receiver assembly with three clamps, tightening the lower clamp first to level receiver. Slide key, located on the indicating arm of the fixture, into the upper gas cylinder spline cut as far as it will go. Pull on the lever, thereby turning the barrel the required distance to bring the indicator to agreement with the qualifying line on the fixture.

Note. Pointer must travel the distance from within lower space cut to qualifying line cut to insure a tight fit,

Then loosen the locking clamps and remove the assembly from the fixture, using a bar placed through the trigger housing opening in the receiver to start the assembly from the fixture.
Source: WAR DEPARTMENT TECHNICAL MANUAL TM 9-1275
The main purpose is to properly "clock" the barrel so the sights & gas system are aligned properly. This is how we were able to tell if the barrel was properly aligned with the receiver. Note how in figure 7 the front is not aligned with the rear. Randall then had to place the receiver and barrel back in the vise and turn it a small amount at a time until the two planes were completely aligned.
Tool Name Price
M1/M1A RECEIVER/BARREL TIMING GAUGES Part # 093-200-010

$76.85

Prior to attempting to headspace the rifle we cleaned out the chamber and barrel completely of all fouling, dirt, and grease. This way we would be able to take accurate headspace measurements. When the bolt was first installed it would not close all of the way. You can see the gap with the small flat blade screw driver inserted in figure 8.
Figure 9 shows the chamber reamer ready to be pulled forward by a long rod. Randall turned a small amount at a time and then would clean before measuring headspace. Once he was able to get the bolt to close and lock properly he stopped reaming and did a full head space test with all three gauges.
Tool Name Price
.308 P/T Reamer Part # 184-300-309

$150.00

Headspace Reaming an M1 Garand

(1) Wipe the chamber thoroughly with a cotton flannel patch before and after each reaming, and prior to each headspace check during reaming. Screw the short adapter deeply into the reamer and tighten lock nut. Dip the reamer in lard oil and insert it into the reamer guide. Make certain bolt lug recesses in receiver and bolt lugs on reamer guide are free from dirt and foreign matter. Place the guide and reamer in the receiver and tighten thumb screw to hold guide in position.

(2) Attach the universal-jointed extension to the reamer and rotate it with a chuck.

Note. If the reamer has been correctly assembled to the adapter it will not cut, but will be held away from the chamber by interference between a should in the guide and the adapter.

Unscrew the adapter from the reamer a little at a time until the reamer begins to cut. Adjusting the headspace reamer is accomplished by loosening the locking nuts, and backing off or advancing the adjusting screw a little at a time, using the field test bolt and headspace Gauge name in the serviceability chart to check for proper adjustment.

When the adapter is correctly adjusted in the reamer, check the tightness of the locking nut. The reamer, once it is adjusted, and if carefully used, will continue to ream to the same dimension until the reamer becomes dull and must be replaced or sharpened.

Note: Any reaming beyond the minimum limit of 1.940 inches reams away a part of the headspace life of the assembly; therefore, make certain all reaming is held to as near the minimum as possible.

Never turn the reamer backward, as such action will chip the lands. Use liberal quantities of lard oil when reaming and wash all chips from the reamer with lard oil each time it is removed from the work. Sharpening stones are furnished for the purpose of keeping the reamers honed properly. Proof fire every rebarreled rifle.
Source: WAR DEPARTMENT TECHNICAL MANUAL TM 9-1275
Figure 10 shows the initial installation of the bolt after final reaming. Note that the bolt is closed and locked.
The 7.62 head space gauges are :
  • GO 1.630"
  • NO GO 1.634"
  • FIELD 1.638"
Tool Name Price
Headspace Gauge Set, GO, NO-GO & FIELD .308 Win Cal.

$59.95

Headspacing an M1 Garand

The headspace of a rifle is measured as the distance between the shoulder of the chamber and the face of the bolt when the bolt is in a locked position. The minimum headspace measurement is 1.940 inches. Headspace is important because it affects accuracy and safety. If the weapon has excessive headspace when the round is fired, the thin portion of the case expands and grips the wall of the chamber, while the base of the case moves rearward to fill the room allowed by excessive headspace and pulls the case in two. This is called a ruptured cartridge case and allows gas to enter the receiver, often severely damaging the weapon. To obtain the headspace measurement, the headspace Gauge is placed on the face of the bolt and so positioned that the ejector enters the clearance cut on the base of the headspace Gauge. If the bolt will close fully on a 1.940-inch Gauge and will not close on the maximum Gauge as specified by the serviceability chart, the headspace is satisfactory.
Source: WAR DEPARTMENT TECHNICAL MANUAL TM 9-1275
A "Go" gauge is the gauge that is used to measure minimum headspace. When you place the "Go" gauge in the rifle and close the bolt, the bolt should close and lock easily and completely.

Figure 12 shows the bolt in place with the op rod removed for the photo with the "Go" gauge installed. Note that the bolt is closed and locked.

A "No-Go" gauge is the gauge that is used to measure the maximum allowed headspace. When you place the "No-Go" gauge in the rifle and close the bolt, the bolt should not close and lock. If the rifle does close on the "No-Go" gauge you may have a problem that needs to be tended to by a gunsmith and may be an unsafe weapon to fire.

Figure 13 shows the bolt in place with the op rod removed for the photo with the "No-Go" gauge installed. Note that the bolt is not closed and locked and you can fit the flat blade screw driver into the gap.

A "Field" gauge is used to measure the largest possible safe headspace dimensions. When you place the "Field" gauge in the rifle and close the bolt, the bolt absolutely should not close and lock. If the rifle does close on the "Field" gauge you have a problem that needs to be tended to by a gunsmith and an unsafe weapon to fire.

Figure 14 shows the bolt in place with the op rod removed for the photo with the "Field" gauge installed. Note the bolt is not closed and locked and you can see the gap easily because it is quite substantial.

Figure 15 shows Randall measuring throat erosion with a breech bore/throat erosion gauge. The gauge's measurements are broken into ten graduations, A serviceable barrel should not produce a reading over 5.  Oddly enough my brand new barrel measured out at just below a 2. Randall said that this is quite common with modern commercial production barrels and it would not impact function or accuracy.
Tool Name Price
Throat Erosion Gauge

$79.95

Inspecting the Breech Bore and Throat Erosion of an M1 Garand

Gauge, breech bore. The breech bore Gauge is used to determine wear of the bore at the origin of the rifling. This Gauge has ten graduations, each of which corresponds to 0.001 inch of wear. The tenth graduation or point marked "REJECT" is equivalent to a bore diameter of 0.310 inch, since the zero graduation is 0.300 inch.

The barrel is inspected visually to determine the condition of the bore and the deterioration that has taken place. A Gauge inspection is then made to determine the amount of wear that has taken place at the origin of the rifling with the breech bore Gauge. The wear in the chamber or in the related parts affecting headspace is checked with a headspace Gauge specified in serviceability chart.

Source: WAR DEPARTMENT TECHNICAL MANUAL TM 9-1275
Figure 16 shows Randall using a tool called a muzzle erosion gauge. It works like the throat erosion gauge but for the other end of the barrel.
Tool Name Price
Muzzle Wear Gauge 

$34.95

Figure 17 shows Randall testing the end of the op rod piston with the gas piston gauge. This gauge checks the diameter as well as the shape of the gas piston. If your gas piston is too small or malformed you will not have a properly functioning gas system. The gauge is slid over the piston and then rotated slowly while inspecting.

Inspecting the M1 Garand Gas Piston

Gauge, no-go piston. This Gauge is used to check the diameter of gas piston.

Source: WAR DEPARTMENT TECHNICAL MANUAL TM 9-1275
Figure 18 shows Randall using the gas cylinder diameter gauge to test the gas cylinder. Luckily mine checked out fine.
Tool Name Price
M1 GARAND GAS CYLINDER GAUGE Part # 093-000-010  

$119.95

Inspecting the M1 Garand Gas Cylinder Diameter

Gauge, gas cylinder diameter. This Gauge is of the plug type. It is relieved on two sides in order to check for out-of-roundness as well as for oversize diameter. The Gauge checks only the origin of the cylindrical portions of the gas cylinder, as this portion has been found to be the one that determines whether or not the cylinder allows the weapon to function properly.

Source: WAR DEPARTMENT TECHNICAL MANUAL TM 9-1275
Randall said, "The standard M1 Garand gas port is 5/64. We drilled our 7.62 NATO barrel to 3/32. I have seen the 1/2 short Beretta barrels along with early BM 59s at 7/64. You can go this large but it is recommended to test the rifle first with several types of ammo and with a solid gas plug (early style) before drilling out to 7/64. The standard M14 gas hole is 5/64 but they use a completely different and better gas system therefore not as much gas volume is needed with a full length barrel."  Note the brass rod inserted into the barrel in figure 19 to prevent the drill bit from over traveling and damaging the bore.
Last, before assembling the rifle Randall used a bolt timing block to check the M1 Garand for correct function. The gauge determines if bolt is closing too early or too late. If the bolt is closing early, it jams on the clip, if too late and it may not close at all. It is clearly marked with release and not release points. 
Randall pressed down on the tool/gauge and allowed the bolt to move forward. The key to measurement is how far down was the gauge depressed before the bolt was released. Mine measured within proper functioning specifications.
Tool Name Price
M-1 GARAND BOLT TIMING BLOCK
Part # 093-222-040

$98.95

Going to the range ended up being a multi-trip endeavor. Not that going to the range multiple times is a bad thing...but it can be somewhat disconcerting if you are doing it because something did not work correctly. The first trip I was a little nervous about loading in the first loaded clip into the magazine and chambering a cartridge. This was not like when you shoot a new rifle for the first time. It was heightened because if everything wasn't assembled correctly then the outcome or consequences could be catastrophic.
I loaded the clip and pushed the op rod handle forward, stripping a cartridge from the enbloc clip and loading it into the chamber. Then I released the safety and slowly took up the slack on the trigger. "Pow!" The first shot rang out! I could see out of my left eye's peripheral vision a spent case fly away. All right!, no one was dead, no missing appendages, and everything seemed to function just fine.

I decided to try another shot. I pulled back on the trigger and a loud "thunk!" emanated from the receiver. I either had a hang fire or an empty chamber. I waited five minutes with the rifle pointing safely down range before I finally gained the courage and pulled the op rod handle back to inspect the chamber....nothing. There was not a loaded cartridge in the chamber. I let the op rod move the bolt forward, stripping another cartridge off of the enbloc clip. I then took up the slack on the first stage of the trigger and then pulled it fully back....."Pow!"...the same thing happened again - the empty case ejected and the bolt did not strip off a cartridge and load it into the chamber. I did this repeatedly with the same results.

Description: You fire a round and the empty cartridge does not eject or it does eject but the bolt does not travel far enough back to strip off a new cartridge to be loaded into the chamber. This is called: "Short-Stroking". This is what happens when the M1 Garand's gas system or a mechanical part that is driven by the gas system is not functioning properly.

Possible Causes of a "Short-Stroking" M1 Garand

  • reloads
  • improper headspace
  • rough chamber
  • bad gas cylinder
  • bad op rod/gas piston
  • Gas port undersized
  • leaking gas cylinder lock screw (gas plug)
  • improperly located gas cylinder
  • severe op rod binding
Source: Fulton Armory
I really thought that there was not much I could do at the range to repair the problem so I went into the clubhouse and disassembled the rifle to see if I could see any evidence of binding or something else obvious that I might be able to remedy while still there. I made certain everything that should have grease did and then reassembled her. I took her back to the line with the hope that I had made some miraculous repair/progress and everything would work as expected. Everything was exactly as it had been before.  I put her back in the case a little sad and started the long drive home.

Randall told me this problem might occur the first time out. That if it did happen then I may need to replace the gas lock screw/valve with a solid screw that would prevent any gas from leaking out the valve. Around 1940 the solid gas lock screw was modified/replaced by a screw/valve assembly as the Garand was transitioned from being a gas trap to a gas port type of operation. On most Garands it is not just a screw but is actually a valve for venting off gas when the rifle is used to fire off grenades. You can tell what type you have by looking at the front of the screw. If the screw head has a single slot then it is a solid screw. If the screw head is cross slotted (similar to a Philips head screw in appearance) then it is a valve type screw.  If you hold the screw and depress with a screw driver while watching the other side you will see a small valve lift up that somewhat resembles a valve in a car's engine. Over the years these valves can become worn and can easily leak gas. This is not really a problem for the most part in a .30-06 chambered rifle because you pretty much have enough gas to spare when fired to drive the gas assembly. In a 7.62 NATO chambered rifle you really cannot afford to have any gas escape out through the valve.

Randall also said that I should make certain that the gas port in the barrel was positioned directly under the vent hole in the gas cylinder. I also spoke to another longtime veteran of Garands who said that an easy way to see if you are losing gas through the valve is to place a piece of tape over the gas cylinder lock screw and if gas was being vented off then the tape would either tear or be blown off. When I got home I examined the rifle closely and I  discovered that the gas cylinder was only exposing about half of the gas port in the barrel. After further examination I found this was caused by the length of the front hand guard I had installed. It was actually about 1/16 to 1/8th of an inch too long. Once I filed away some of the lip (wood) on the rear of the hand guard I was able to fit the gas cylinder's vent hole directly over the port in the barrel. I was certain this was the culprit and prepared to return to the range the following Saturday morning.

Something I should have mentioned before.....during my first visit to the range and because I was shooting a brand new barrel I followed the Krieger Barrel's Break-in & Cleaning instructions for breaking in a new barrel.

 

Why is the Break-in & Cleaning process important when first shooting through a new barrel?

When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this gas and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it; copper which adheres well to itself, will build up quickly and may be difficult to remove later. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it; copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat polished without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" procedure.
Source: Krieger Barrels, Inc.
In my range kit I took along a solid cleaning rod, a new .308 brush & jag, .30 cal patches, and an M1 Garand bore guide as well as an ample supply of Ed's Red bore solvent.

Step 1) I fired a single shot followed by a thorough cleaning. I repeated this process five times. The instructions state that if the fouling is still prevalent then you would want to repeat this "one shot and then clean" process another five times or until the fouling was minimal after shooting. After I completed my five "shoot and clean" steps I started to see a reduction in the amount of fouling I found in my barrel so I continued onto the next step in the process.

Step 2) I then fired a three shot group followed by a thorough cleaning.

Step 3) Then I fired a five shot group followed by a thorough cleaning. I could not see a lot of fouling at this point so I moved onto regular shooting.

This is not intended to be a comprehensive set of instructions for breaking-in a new barrel. Your barrel may take less or more steps until it is broken-in properly than my barrel did. I really just wanted to point out the importance of taking the time to properly break-in any newly installed rifle barrel.

The second trip to the range I decided to take some spare parts. Well, actually I took another whole Garand with me for parts. With trepidation I loaded in my first clip. I really did not want to have to go back to the drawing board for answers, but I was fairly certain I had corrected the problem. I fired off my first round and everything worked great! The spent case ejected and another loaded into the chamber. I fired again. This time the spent case did not eject but a new cartridge was stripped off of the enbloc clip and the rifle attempted to chamber it.
It rested up against the primer of the spent case that was lodged into the chamber. I pried out the case and loaded up again. The same thing happened again. Crap! I repeated this several times more. It seemed as though the gas system was working fine, but the cases were just not being extracted from the chamber. I had nothing to lose, so I grabbed my other rifle and pulled out the bolt. Next I removed the extractor and extractor plunger from the bolt. After a while I had replaced these parts on the bolt of my new Garand and had everything reassembled.
I really hoped that my hunch was correct. I loaded a clip, chambered a cartridge, flipped the safety off and pulled the trigger. I repeated this same series of steps seven more times without any malfunction.  "Tang!" The empty enbloc clip popped out of the receiver. I smiled and loaded up another. Eight more shots rang out without any interruption or error. I was a very proud man! My new creation (and Randall's) had finally worked the way she was designed to. Now I could focus on accuracy. Heck, I had not even looked at the target yet. What I found was not too bad and was a great place to start now that I had a rifle that would function and shoot consistently.
By the end of the day I had shot another dozen or so clips through the rifle and had a big grin on my face as I loaded up and headed home.

I have come to the conclusion that if you are planning on building a single M1 Garand that it is not cost effective or practical to attempt the project on your own. It is much more economical and safe to have a qualified and skilled individual build it for you. The required equipment and gauges can actually cost you in the thousands of dollars to properly set up your bench. That is if you can find everything.

 

There are several companies online that offer services from installing a barrel on your receiver to completely building a custom M1 Garand.
 
Here are just a few:
 
http://www.dgrguns.com/
http://www.fulton-armory.com/
http://www.smithenterprise.com/
http://www.garandguy.com/
 

Adobe PDF Downloadable Version of Article

 
Article by Jamie Mangrum
 
Additional Article Resources:
http://www.billricca.com/serv03.htm
 
http://www.rule762.us/product_pages/gun_parts/m1_garand.htm
 
PALADIN PRESS "COMPLETE M1 GARAND: A Guide for the Shooter and Collector"   by Jim Thompson
 
Scott A. Duff's "The M1 Garand: Owners Guide"
 
PALADIN PRESS: CLASSIC M1 GARAND An Ongoing Legacy for Shooters and Collectors by Jim Thompson