I am currently working on sporting up a '93 Mauser and am down to installing the new barrel. I am going with a Shaw barrel in 7X57 mostly due to price and the good things I've heard about the company. I've got the reamer but I have a question about finishing out a short chambered barrel. Some barrel makers say that they leave the last .05" to be finished but most books say to do approximately the last .005" by hand. I would like to hear from someone who has done this how much is practical to remove by hand. .050" isn't much until you start cutting the full surface of a chamber. I don't have access to a lathe and really want to do it myself anyway. Any information based on experience would be great. Any pitfalls that I might encounter would be good too. Thanks in advance!
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Finishing a short chambered barrel??
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There are no mysteries to chambering a barrel, knowing where you are at all times is most important, I chamber first then install, I establish the chamber, measure case protrusion, measure the bolt face to receiver ring. Knowing where you are? I make gages from .017 under to .016 over a go-gage, this system works for me, if the barrel is installed head space is known to the thousands, not somewhere between go and no-gage size, or beyond.
Lathe and force chambering, the reamer has a pilot, this gives it a mind of it's own, I use a lathe to hold a barrel for chambering, muzzle in the chuck and chamber centered with a collet on the gear end of the lathe. I hand ream all my chambers.
What part of Texas?
F. Guffey
Lathe and force chambering, the reamer has a pilot, this gives it a mind of it's own, I use a lathe to hold a barrel for chambering, muzzle in the chuck and chamber centered with a collet on the gear end of the lathe. I hand ream all my chambers.
What part of Texas?
F. Guffey
There is no exact amount you will need to cut for that chamber. You can use a pull through reamer, but that is pretty expensive for a one-off job.
I think you will be OK if you install the barrel, then check with a GO gauge first. Then (assuming the gauge doesn't fit), just take out a little at a time and check frequently with the GO gauge. You can feel when you are getting close and when the GO gauge fits, you are done. (It should go without saying, but wash chips out of the chamber and off the reamer before using the gauge and making another pass.)
Making your own gauges and trying to achieve some magic measurement is OK, but unnecessary.
Jim
I think you will be OK if you install the barrel, then check with a GO gauge first. Then (assuming the gauge doesn't fit), just take out a little at a time and check frequently with the GO gauge. You can feel when you are getting close and when the GO gauge fits, you are done. (It should go without saying, but wash chips out of the chamber and off the reamer before using the gauge and making another pass.)
Making your own gauges and trying to achieve some magic measurement is OK, but unnecessary.
Jim
Let me rephrase my question. I wouldn't think that it would be practical to remove 1/2" of metal by hand reaming. What IS practical? If the barrel is short chambered .050" and I end up having to take .020" off the barrel shank, That leaves me removing .070" by hand to finish the chamber. Is that a lot??? Most of my books talk about removing the last .005"-.010" by hand. Hope this helps clarify and thanks for the info. so far.
I quit reading those books and articles, the bolt closes, the chamber gets dark, after that they claim no one knows where there are when finishing a chamber, so check often, ream a little, check a little.
Hand finish? The reamer will need to be turned with something, I have extensions and 'T' handles, hand tools, cutting oil must be used, reaming does not require effort, with the barrel supported on it's end, the weight of the reamer and T handles is all that is required, I would suggest getting a depth micrometer or dial caliper.
No mysteries to chambering and there is no excuse for not knowing how short a chamber is, you are going to shoot ammo, not gages, use a full length sized case (no powder, primer, bullet), install the bolt, rotate and seat the lugs then pull the bolt back, measure from a flat on the receiver to a flat on the bolt, recording reading, repeat this procedure with the full length size case, the difference between the two measurements will tell you the amount of metal to be removed before the bolt will close. .005 is the difference between a full length sized case and a go-gage, therefore a go-gage can be used to determine how short the chamber is in thousands, it is not in the book. And, when finished, the lateral travel of the bolt (back and forth) will indicate head space, no travel, no head space, a lot of travel, a lot of head space (on some rifles), in the perfect world with the perfect chamber and a go-gage chambered, the bolt will have .000 lateral movement, with the perfect cartridge the bolt will have .005 lateral travel.
I am not that far from you, if I can help let me know. I am not sure what you had in mind when you said you could remove metal etc., removing metal from the face of the barrel will increase case head protrusion, on a Mauser case head protrusion is .110, if for some reason you face off the barrel, move the shoulder at the end of the threads forward the same amount..
F. Guffey
Hand finish? The reamer will need to be turned with something, I have extensions and 'T' handles, hand tools, cutting oil must be used, reaming does not require effort, with the barrel supported on it's end, the weight of the reamer and T handles is all that is required, I would suggest getting a depth micrometer or dial caliper.
No mysteries to chambering and there is no excuse for not knowing how short a chamber is, you are going to shoot ammo, not gages, use a full length sized case (no powder, primer, bullet), install the bolt, rotate and seat the lugs then pull the bolt back, measure from a flat on the receiver to a flat on the bolt, recording reading, repeat this procedure with the full length size case, the difference between the two measurements will tell you the amount of metal to be removed before the bolt will close. .005 is the difference between a full length sized case and a go-gage, therefore a go-gage can be used to determine how short the chamber is in thousands, it is not in the book. And, when finished, the lateral travel of the bolt (back and forth) will indicate head space, no travel, no head space, a lot of travel, a lot of head space (on some rifles), in the perfect world with the perfect chamber and a go-gage chambered, the bolt will have .000 lateral movement, with the perfect cartridge the bolt will have .005 lateral travel.
I am not that far from you, if I can help let me know. I am not sure what you had in mind when you said you could remove metal etc., removing metal from the face of the barrel will increase case head protrusion, on a Mauser case head protrusion is .110, if for some reason you face off the barrel, move the shoulder at the end of the threads forward the same amount..
F. Guffey
First off, you are reading (interpretating) the numbers wrong. .500 is half an inch, not .050. Most short chambered barrels are about--about--.025 short. That isn't a lot, even if it's .050 short. One of the hairs off your head will measure about .005 to .008--depending if you're a Swede or an Italian--or whatever. Anyway, install the barrel (tight, in it's final place), then, using plenty of oil, ream a little, clean very well and then check with a gauge. As to a gauge, unless you're making a match rifle, then a factory loaded shell will work just fine. When the bolt (with firing pin removed) will smoothly close on a factory shell, you are home. Yes, GO/NoGo gauges are great and primo, but quite expensive for a one time deal, and a factory loaded shell will do just fine. They are virtually always on the small side of the specs, because the factory wants to be sure their shells load in everyones gun. Consequently, you won't make an overize chamber as long as you stop as soon as a factory shell will chamber. I suppose to be all-pro, you might use several different shells from a few different sources. I've never gone to that extreem, and I'm yet to screw up. The statement above regarding "ream a little" is to be observed. We are really talking small amounts of metal removal here. It is better to remove too little and check several times than to remove too much (disaster). You do need a reamer extension turner, but you probably have what will suffice in your 3/8 socket set. Cut with light preasure 1 turn between checks. With the needed extensive cleaning between checks, it may take a few minutes, but what is an hour to do it right? Just be slow and patient. It's not a big deal, really, and once you do your first chamber, you'll be quite proud of youself.
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moosehunt, thank you for taking the time, I purchased a mill from a collector of Garands and Springfields (plus), while getting the parts gathered up and loaded he mentioned the he was building a Springfield with correct parts but was having trouble with the head space procedures and had given up on getting help (or helping) through the Internet. The collector is an outstanding resource person, it just does not take him long to look at it to tell if it is correct or mixed.
As to head space on his rifle, I told him it was his lucky day, I told him I could check head space on a Springfield 3 different ways, he handed me a set of head space gages, I informed him that was not one of the ways. The rifle he was building required a straight handle bolt, he had one therefore he was limited. He had purchased a new box of Remington 30/06 ammo to test fire, the effect the new ammo had on head space was .0065 to .0075, not likely but had we tested the effect different bolts had on head space we could have reduced the head space. I then wanted all the loaded 30/06 ammo he had available, I explained to him we were going to check the effect each had on head space, he said he did not have a tool for that purpose, I explained to him he did or we would make one, he did, he just did not recognize it. There is not much that can be done with a chamber that is between a go-gage and no-gage length, unless the the head space can be off set with the effect the case has on head space, or swap bolts?
He and other collectors are building a data base for parts, stamps and markings, I took 30 Springfield bolts I acquired from the Western Scrounger in order for the information to be added, all were bent handles and none of the bolts would change head space more than .005, he has 75+ bolts, I offered to check each for the effect it had on head space, again none of his bolts had a straight handle.
He ask me If I had ever gotten involved in a discussion on a forum regarding head space or cutting a chamber, I said yes, and I told him could look at the question before the first response and tell him how it would end.
Moosehunt, thank you for your contribution.
F. Guffey
As to head space on his rifle, I told him it was his lucky day, I told him I could check head space on a Springfield 3 different ways, he handed me a set of head space gages, I informed him that was not one of the ways. The rifle he was building required a straight handle bolt, he had one therefore he was limited. He had purchased a new box of Remington 30/06 ammo to test fire, the effect the new ammo had on head space was .0065 to .0075, not likely but had we tested the effect different bolts had on head space we could have reduced the head space. I then wanted all the loaded 30/06 ammo he had available, I explained to him we were going to check the effect each had on head space, he said he did not have a tool for that purpose, I explained to him he did or we would make one, he did, he just did not recognize it. There is not much that can be done with a chamber that is between a go-gage and no-gage length, unless the the head space can be off set with the effect the case has on head space, or swap bolts?
He and other collectors are building a data base for parts, stamps and markings, I took 30 Springfield bolts I acquired from the Western Scrounger in order for the information to be added, all were bent handles and none of the bolts would change head space more than .005, he has 75+ bolts, I offered to check each for the effect it had on head space, again none of his bolts had a straight handle.
He ask me If I had ever gotten involved in a discussion on a forum regarding head space or cutting a chamber, I said yes, and I told him could look at the question before the first response and tell him how it would end.
Moosehunt, thank you for your contribution.
F. Guffey
Thanks for the reply moosehunt. I had the numbers correct. I mentioned 1/2" to make the point that I thought that it would be extremely difficult to remove 1/2" or .50" by hand reaming. I was just unsure of how easy it was to remove .050" by hand reaming. My books say to remove .005" by hand reaming. I have never used a chamber reamer before and have no idea if it would take 5 minutes or 5 hours to remove .050" by hand. I think what I'm looking at is about .070" and it seems that most folks think that it won't be too bad.
Fguffey--- The reason I may have to shorten the barrel shank is to provide clearance for the bolt lug and extractor. The barrel shank comes .645" and I've got .632" to the top bolt lug after trueing the receiver torque shoulder.
Fguffey--- The reason I may have to shorten the barrel shank is to provide clearance for the bolt lug and extractor. The barrel shank comes .645" and I've got .632" to the top bolt lug after trueing the receiver torque shoulder.
"The barrel shank comes .645" and I've got .632" to the top bolt lug after truing the receiver torque shoulder".
Next time, install the bolt and measure from the front receiver ring down to the bolt face, record the measurement, always, if you face the front receiver ring to square it up up you can install the bolt again and take another measurement, the difference will indicate the amount of metal removed. then you can face the barrel an equal amount.
I check case head protrusion on barrels when they are removed, I measure the distance from the front receiver ring down to the face of the bolt, as I said before case head protrusion on a Mauser (98) is .110 +or- very little, the .110 allows for the extractor, and protruding metal on the front of the bolt, you changed all of that.
This is not as involved as installing a M1917 barrel on a P14 with the problems presented with the bolts, problem solved with a lathe, not knowing the amount of metal removed from the front receiver ring means it will be require cutting a little then check,you know the minimum amount of metal required will be .013 thousands + crush (removing slack between the threads). I would remove .020 thousands, install the barrel then determine if the bolt + the extractor will clear the face of the barrel.
Sooner or later you will measure from the receiver ring down to the bolt face, according to you measurements the reading will be .645 + case head protrusion + head space. Given the opportunity I would have discouraged you from cutting the receiver back.
F. Guffey
Next time, install the bolt and measure from the front receiver ring down to the bolt face, record the measurement, always, if you face the front receiver ring to square it up up you can install the bolt again and take another measurement, the difference will indicate the amount of metal removed. then you can face the barrel an equal amount.
I check case head protrusion on barrels when they are removed, I measure the distance from the front receiver ring down to the face of the bolt, as I said before case head protrusion on a Mauser (98) is .110 +or- very little, the .110 allows for the extractor, and protruding metal on the front of the bolt, you changed all of that.
This is not as involved as installing a M1917 barrel on a P14 with the problems presented with the bolts, problem solved with a lathe, not knowing the amount of metal removed from the front receiver ring means it will be require cutting a little then check,you know the minimum amount of metal required will be .013 thousands + crush (removing slack between the threads). I would remove .020 thousands, install the barrel then determine if the bolt + the extractor will clear the face of the barrel.
Sooner or later you will measure from the receiver ring down to the bolt face, according to you measurements the reading will be .645 + case head protrusion + head space. Given the opportunity I would have discouraged you from cutting the receiver back.
F. Guffey
I can assure you I did not remove much as I have no lathe and was working by hand. I guess trueing was the wrong word to use. I simply removed a pulled thread that was sticking out after removing the barrel and polished the torque shoulder using abrasive taped to a sheet of glass. Not the best way I'm sure but I've learned to make due with what I have.
Try this, screw the barrel into the receiver, if the threads are clean and have clearance, the barrel should bottom out against the shoulder at the end of the threads, you could go to hand tight, then install the bolt and close, if it closes, that's good, if it does not close back the barrel out until the bolt will close, then measure the gap between the receiver and shoulder at the end of the shank with a feeler gage, the thickness of the gage that fits the gap will indicate the amount of metal required for clearance (plus a few for crush).
F. Guffey
F. Guffey
I'm thinking that you are getting way ahead of yourself and creating possible problems that aren't likely. If that's all you did to the reciever, and you are getting a Shaw short chambered barrel, I think you will have no problems, provided you ordered the correct barrel. Really, I think all you need to do is get that chamber reaming completed, as described earlier. Maybeso you are reading too many books!
Moosehunt, you are probably right!! I'm a bit of a perfectionist and often try to forsee the problems before they present themselves. I'll order the barrel and have a go at it. Thanks for all the help.
P.S. The books also say not to build a sporter on a Spanish Mauser action. I guess I should have stopped there if I was going to believe everything I read.
P.S. The books also say not to build a sporter on a Spanish Mauser action. I guess I should have stopped there if I was going to believe everything I read.
"I am currently working on sporting up a '93 Mauser and am down to installing the new barrel", like you before I can install, I have to acquire.
Building a small ring Mauser, Brownell's list barrels (chambers) that are available for small ring actions, they list 2 small ring barrels that are chambered in 308 W and 30/06 for the Turk 38 only, there are many options when it comes to chambers for the small ring/small shank action, the 7X57 and 6.5X55 in my opinion is at the top of the list, because of cheap/available ammo some are going to the 7.62X39.
F. Guffey
Building a small ring Mauser, Brownell's list barrels (chambers) that are available for small ring actions, they list 2 small ring barrels that are chambered in 308 W and 30/06 for the Turk 38 only, there are many options when it comes to chambers for the small ring/small shank action, the 7X57 and 6.5X55 in my opinion is at the top of the list, because of cheap/available ammo some are going to the 7.62X39.
F. Guffey
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