Re-Barreling M1 Garands

By Ryan M. Davis
Cross Saber Custom Gunsmithing LLC
Kouts, In

Over the last couple years I have worked on several of the local Veteran organization’s M1 Garand rifles. Not too long ago I had five of these rifles brought into the shop by a local American Legion. These rifles were actually having issues with the BFA’s (Blank Firing Adapters) flying off of the muzzle during ceremonies. The last one was shot into a crowd, luckily with no injuries.

I took in the rifles and first thing pulled off the BFA’s to examine the barrels. The threads on the muzzle end of the barrel were all nearly completely worn off. I measured the pitch diameter and major diameter on all five of the barrels; the threads were severely out of spec.

At I first tried replacing the BFA’s with newly manufactured ones, hoping that one “in-spec” thread would work with the out of spec. On one rifle the threads were so severely worn that I could pull the new BFA off of the barrel without unscrewing it, just by wiggling.   All of the rifles were very loose fitting with the new BFA’s installed and I felt they too may fly off under pressure. I called my point of contact with the American Legion and we went over different options. We finally decided on replacing the barrels and BFA’s on each rifle.

I wanted to add an after note since I wrote this. These rifles were being fired with the proper issued crimped ammo. If you do not know what I am talking about and you work on or shoot M1 Garand rifles that fire Blank ammunition. Do a web search, it may save your rifle and even your life. It seems that there is a bunch of Grenade Launching blanks floating around and some Veteran organizations have had severe issues with firing the wrong ones with BFA’s attached. Do your research.

Since these rifles are actually property of the US Government and are only lended to the Veteran organizations, we had go up the chain to get permission for the work to be done. When my contact from the Legion came in with news, he reported that the rifles could be serviced, to include re-barreling, by any licensed gunsmith. Since I have done work with this particular American Legion before and the shop is federally licensed, they had me go ahead and change out all five barrels.

I thought I would take this opportunity to show you all how I changed these barrels.

This is how I did it and I also will show some tricks I have learned in the past. This is by no means the only way to do the job, but it is how I have come to do it. This way has worked with me before and it is the best way I have figured out how to do it with the tools I have at hand. You may know a better way that works for you and that’s great. This is the best way I have figured out to do it though.

If you are looking for work in say a new shop or during the slow season, the Veteran organizations are a great place to get work. Many of my local organizations perform a lot of ceremonies where they fire their rifles, some as many as 75-80 ceremonies a year. Many of these organizations do not have someone qualified to even clean these rifles, let alone service them. This was a good opportunity for me when work was slow before many people new I was here.

I started by completely disassembling the rifles. While being sure that each of the rifle’s components were separated and neatly organized as not to mix the parts between the rifles. If you do not know how to disassemble an M1 Garand you can go to the Civilian Marksmanship Program’s website. They do a good job of showing this process, so I will not go into it here. And of course there are the wonderful videos that AGI offers, I mean that is why we are all here. Once disassembled the only parts needed to be left out and accessible are the barreled action, new barrel, bolt and the gas cylinder.

For the next step I needed a barrel vise and action wrench. Both of which were made by me in the shop, but the like can also be purchased from several companies. Just do a search online, you will find many.

This is the shop made barrel vise that I used. You can make one like this or buy one. Whatever your skill level/wallet may allow.

This is my shop made action wrench. As you can tell I make new heads for different actions as I need them and this head is newer than the handle. Brownells also sells an entire interchangeable action wrench set-up. Once again your choice/abilities/budget.

Note: It is very important to have a proper action wrench attached correctly along with a correctly fitting barrel vise or you may damage the receiver and or the barrel.

I set-up the barreled action in the vise and then secured the vise so the action could be broke loose. I then attached the action wrench onto the action making sure the two legs on the bottom of the receiver are both touching the wrench equally. As I tightened the two bolts I ensured that both pieces of the action wrench were parallel creating equal pressure on the receiver. Once properly set-up I was able to break each receiver loose without a breaker bar, though some were close.

Once they broke loose I was able to remove each receiver by hand.

Once each receiver was removed the barrels were marked and set to the side. The new barrels were manufactured by Criterion and were sold to me by Dean’s Gun Restorations. They had a good deal on the same product that was available everywhere else for more. The new barrels and old receivers were cleaned well. The old receiver had years of powder residue from shooting blanks and the new barrels were coated in some kind of rust preventative. I was sure to clean these very good as anything left dirty could cause problems with the re-barreling process.

While with the receiver it is obvious, the barrel too needs cleaned well because it is coated in a rust preventative that is barely visible.

Once everything was clean and dry, I set a new barrel up in the barrel vise and re-secured the vise. I then placed a drop of oil on the clean barrel threads beforehand screwing the receiver on to the barrel shank. The receiver should stop round the 10:30-11:00 mark like shown below. The receiver will be turned the rest of the way with the action wrench installed. Once again I paid special attention to the way the wrench was against the receiver.

Note: It is very important to have a proper action wrench attached correctly along with a correctly fitting barrel vise or you may damage the receiver and or the barrel.

I Know I put this twice, but it is that important!

Once everything was set up, I tightened the receivers until they were properly timed with the barrels. With M1 Garand rifles, if the barrels are off top dead center by even a couple degrees, you could have a rifle that is impossible to zero once finally assembled. I used an angle finder to ensure that the barrels and receivers were properly aligned. To check this you could get a special tool that is specifically designed for this exact task but I do not have one. I use the gas cylinder attached to the barrel. Be warned that most new barrels will require some finessing to get the gas cylinder on, even worn gas cylinders are somewhat tight on some new barrels. With the barreled action still in then secured vise, gas cylinder installed and the front sight removed, I set the angle finder on the flat for the front sight and make not of the reading.

To align the receiver I have used different methods. I like to set my angle finder on the two flats at the bottom of the receiver in line with were the locking lugs are in battery. I have also used the rear sight, both setting the angle finder on the sight wings and also on a gage block in the rear sight recess. Whichever way you go about it, an easy way to check if you’re aligned is to take two pieces of straight drill rod at least 12” or so each. Put one through the holes in the ears of the rear sight portion of the receiver. Put the other on the flat at the rear of the front sight dovetail.

Once you have both rods in place you can look across the two and see if they are parallel.

I know the glare makes it difficult to tell in this picture, if the rods are parallel. They are indicating the timing is good. If your bars are not parallel and your indication method shows it should be, go back and look for burrs or some other kind of interference in your indicating plane.

Once your barrel is timed correctly remove it from the vise. You will most likely notice that the shoulder portion of the barrel may change color or look distorted; this is normal and is the result of swaging the shoulder against the receiver. This is how the barrel stays locked into the receiver with all the vibrations resulting from being shoot time over time again.

The next step is to completely disassemble the bolt and clean it very well. Any dirt or debris may give false headspace readings and result in an overcut chamber. Don’t forget to clean all around the locking lugs and where they lock in the receiver. Also double check the chamber area, although we cleaned it all before the installation of the barrel, it may need re-cleaned to be safe. Take the cleaned stripped bolt and install it into the clean barreled action.

I like to hold the barrel about 4”- 6” from the receiver in a padded vise. Once everything is setup it is time to start cutting the chamber. Since the Criterion barrels are short chambered, I will be using my pull through Clymer reamer set-up and a set of Clymer headspace gages. I bought all of the tools for this part through Brownells and they have worked wonderfully for me ever since. It is great quality tooling.

Once the barreled action is secured in the vise with the stripped bolt installed and everything clean, I checked the existing headspace of the short chamber.

This is how far the bolt would close on the Go gage with the untouched short chamber

Note: Leave the NoGo gauge in the package until the chamber closes on the Go gauge. The last thing you want is to cut the headspace to the wrong dimension because you accidentally grabbed the wrong gauge off of the bench.  

None of the bolts closed on the Go gauge as expected, yet it is better safe than sorry. I placed the extension rod through the muzzle and down the bore. I then move the bolt to the rear most position and then insert the reamer into the action. Carefully, I align the reamer with the threaded portion of the extension and begin to screw the extension into the reamer. I am careful not to cross thread the two while ensuring the reamer does not touch anything with the flutes.

The reamer is held outside of the chamber to ensure no damage occurs to the reamer

Once secured I pour cutting oil onto the reamer while rotating the extension by hand clockwise (looking from the muzzle to the receiver) to ensure the whole reamer has a good coat. Once the reamer is coated in oil I place the bushing onto the rear of the reamer and close the bolt until it touches the bushing.

While turning the extension clockwise I begin to pull the reamer into the existing chamber while also holding slight pressure on the bolt causing it to follow the bushing.

Note: If you do not keep constant light pressure on the bolt and the reamer pulls away from the bolt face, you could cut the chamber too deep and will have made a mess. If you push too hard you will dig the cutting edge of the reamer into the chamber possibly causing damage to the tool, barrel or both. The bushing works as a spacer, but this spacer will only work if the bolt, bushing and reamer maintain light contact with each other.

With the bolt all the way forward against the bushing with the reamer completely in the chamber. If you notice it is nearly the identical position of the go gage pictured above.

The reamer is removed and cleaned every few turns of the extension.

I always make it a point to stop just a little shy of the bolt closing and cleaning everything out very well. I do not want a chip or some debris to give me false readings from by bushing.

I want the bolt to just close and not more. You will feel the tool start to spin freely when the bolt reaches full battery. Do not force it farther.

Once the bolt is right where I want it I clean everything up and check the headspace with the Go gauge. As long as everything checks with the Go gauge I get out the NoGo gauge and check that.

Pictured above is the bolt closed on the Go gauge on the left, and the NoGo gauge is pictured on the right.

Once the headspace has all checked out, I reassembled the rifles and they were now ready for test firing the new barrels. The BFA’s need to be tuned and there is some information on that over at Fulton Armory’s website (not as much on this subject available on the web). This is also where we bought the BFA’s for this project. I will not go into the process of tuning BFA’s because that is not in the scope of this article. I was more concerned with showing the way I re-barrel an M1 Garand.

I want to explain that this is not the way I would do this job if it were to be built into a competition rifle. I would not start with a short chambered barrel and all the work would be done in the lathe with the proper setup. Not all rifles are built for 10 rings and definitely not all customers want to pay for rifles that are. So if someone want’s their plinker, reenactor, ceremony or even hunter re-barreled this process will definitely do the job well.

Thanks for taking the time to read my article and if you have any comments, suggestions or questions feel free to let me know.

3 Responses to Re-Barreling M1 Garands

  1. WOW, you are good!
    AWESOME article Ryan, and really good pictures also!
    I’ve never done anything like this before but the article is so well written (detailed) and the pictures are so good that I totally understand the whole process from start to finish. I really like the tips along the way too.
    I also understand that these types of articles take SEVERAL HOURS to produce!
    Awesome gunsmithing. Excellent article and many thanks to you Ryan for sharing!

  2. Great article! I was privileged to attend the Advanced Maintenance Class at CMP’s Custom Shop in Anniston, Al this past August. The procedure that we used to install the barrel to the receiver, etc. during the class was identical to what you showed in this post. We used rods across the front and rear sights (as you showed) to get the timing right, not an angle finder. The only difference is that we lapped the bolt lugs first to ensure that both lugs evenly and fully contacted the receiver before installing the barrel and setting headspace. This step is probably necessary only if you are also installing a new bolt at the same time as a new barrel, but it wouldn’t hurt to check and make sure that both bolt lugs engage the receiver before using the reamer to set headspace.

    The CMP eStore is a good source for both barrel vises and receiver wrenchs. The receiver wrench CMP sells has cuts on three sides – one for the 1903/A3, one for the M1 Garand, and one for the M1 Carbin

  3. I was advised to put a Criterion Barrel on my worn out M1 because of getting the headspace correct with an older barrel and the bolt. By reading and seeing your article I see why he did it. Very intelligent and hands on, hats off. I enjoy seeing and reading about this so I can understand the problems and the time required. I’m very impressed, Patrick.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.