Threading a barrel without taking barrel off?

This is a question that will be debated a much as 30-06 vs 270. Barrel in headstock vs barrel between centers. There are many advantages to do it either way. Pick which ever one suits you best. I choose to do it in the headstock. It is a much more Ridgid setup. I believe it's more precise. And with all the tooling I designed and built for chambering and crown work using this method it is faster for me. I have no issue doing it between centers as that is how I was taught in school. I would never tell someone they are wrong to do it that way. My thoughts on what the achieved differences are as follows.
Between centers will give you a barrel that runs straight down center line from the receiver center line. Between centers will not make the most precise chamber or crown. Only if the bore hole is perfectly straight down the center of the barrel can it be done perfect with this method. And we all know barrel holes are not perfectly straight down the center.
In the headstock method it is a very Ridgid setup and makes cutting threads much faster and smoother. This method allows you to make the straightest chamber and crowns. Barrel straightness will have no effect on how straight your chamber is to the bore. Because you are going to make perfectly straight the part of the bore that the chamber is going to be it has to be straight. One thing about this method is the barrel will need to be indexed to top dead center or bottom dead center. The barrel will not point exactly straight down the receiver line. Unless the barrel and bore are straight. I can tell you they are not straight. Nobody's barrels are perfectly straight.
These are my opinions and they are shared by many. I'm not saying one should do it my way. I'm not arguing one over the other. Just stating some facts about it. Do as you choose is the way for you.
I would pick the 30-06 by the way because it was my first deer rifle.
Shep
 
gusd said:
I always assumed the barrel needed to be taken off in order to thread the muzzle ?
Is this correct, or is it like I just read on a different thread?
"Any gunsmith that can't thread a barrel without removing it shouldn't be a gunsmith."
Click to expand...
As a retired tool and die maker with plenty of experience(over 45 years) running all types and sizes of engine lathes I will add my two cents worth. I would not attempt to thread a barrel which would be brass shimmed in a four jaw chuck unless I separated the barrel from it's action and here is my reasoning.Assuming that you had a lathe with a long enough tail and head once the barrel has been chucked up and indicated to dead zero(Trued Up) consider this, behind the tail the barrel and it's action will be turning at lets say 350-425 RPM. While on the other end you would have a barrel which usually has a tapered contoured OD. Now even though held in place by the chuck jaws as well as a steady rest you will have a certain amount of vibration emanating from the end attached to the action. All this is happening while you are trying to first turn the muzzle end of the barrel to lets say .625" Diameter for a 5/8" X 24 TPI. Once that has been done you must change tool bits as well as the compounds angle to 29 1/2 degrees. After that you must set the lathe to thread the correct number of threads and take a skim cut in order to verify that in this case cutting 24 threads per inch. Stop and after clearing your tool bit check your pitch by using a Thread pitch Gage. After that you will continue to thread the barrel by lets say .005" increments until you start seeing metal beginning to curl off your tool bit. Now you must apply a cutting lubricate to the barrel while chasing down your threads in lets say .002" increments to a given depth that you have trigged out before hand. All the time the barrel is still spinning with the barrel's action still attached and is flexing ever so slightly. This flexing or oscillation is transmitted the entire length of the barrel all the way to the muzzle. Yes it is negated by the steady rest to the point that you may not notice it,however if you were to place an indicator on the end of the barrel just ahead of the barrel nut and turn the barrel by hand you will see the indicators finger move from high to low, hence run out. Compound this by the lathes internal wear and opening up of it's tolerances and you may have the perfect recipe for disaster.
Mind you while you are cutting threads your attention is only on that particular operation and you really do not want to think about anything else much less vibration or barrel flex. It is so easy to have a lathe jump or skip a portion of a thread while cutting them why would you want to take a chance on cutting into a thread with a partial deforming of its crown? I for one would want as many potential problems taken out of the equation before hand, and once properly set up keep my head into the threading of the barrel only.
To that end I would separate the barrel from it's action before chucking up and indicating said barrel prior to turning and threading.
There are just to many things that that you must take in to account before you even start the threading of the barrel,and I myself will stack the odds of success in my favor. So for my money I would strip everything off the barrel that I could ( including the trigger assembly) in order to prevent even the smallest amount of barrel run out or barrel movement in any way.
Why take the chance on messing up an expensive barrel? I would treat it as if it were a brand new barrel and follow a prescribed method of achieving success. Just my thoughts !
 
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Blackhawk said:
As a retired tool and die maker with plenty of experience(over 45 years) running all types and sizes of engine lathes I will add my two cents worth. I would not attempt to thread a barrel which would be brass shimmed in a four jaw chuck unless I separated the barrel from it's action and here is my reasoning.Assuming that you had a lathe with a long enough tail and head once the barrel has been chucked up and indicated to dead zero(Trued Up) consider this behind the tail the barrel and it's action will be turning at lets say 350-425 RPM. while on the other end you would have a barrel which usually has a tapered contoured OD. Now even though held in place by the chuck jaws as well as a steady rest you will have a certain amount of vibration emanating from the end attached to the action. All this is happening while you are trying to first turn the muzzle end of the barrel to lets say .625" Diameter for a 5/8" X 24 TPI. Once that has been done you must change tool bits as well as the compounds angle to 29 1/2 degrees. After that you must set the lathe to thread the correct number of threads and take a skim cut in order to verify that in this case cutting 24 threads per inch. Stop and after clearing your tool bit check your pitch by using a Thread pitch Gage. After that you will continue to thread the barrel by lets say .005" increments until you start seeing metal become to curl off your tool bit. Now you must apply a cutting lubricate to the barrel while chasing down your threads in lets say .002" increments to a given depth that you have trigged out before hand. All the time the barrel is still spinning while the barrel with the action still attached is flexing ever so slightly. This flexing is transmitted the entire length of the barrel all the way to the nuzzle. Yes it is negated by the steady rest to the point that you may not notice it.however if you were to place an indicator on the end of the barrel just ahead of the barrel nut and turn the barrel by hand you will see the indicators finger move from high to low, hence run out. Compound this by the lathes internal wear and opening up of it's tolerances and you may have the perfect recipe for disaster.Mind you while you are cutting threads your attention is only on that particular operation and you really do not want to think about anything else much less vibration or barrel flex. It is so easy to have a lathe jump or skip a portion of a thread while cutting them why would you want to take a chance on cutting into a thread with a partial deforming of its crown? I for one would want as much of the what if taken out of the equation and once properly set up keep my head into the threading of the barrel only. To that end I would separate the barrel from it's action before chucking up and indicating said barrel prior to turning and it' threading.
There are just to many things that that you must take in to account before you even start the threading of the barrel,and I myself will stack the odds of success in my favor. So for my money I would strip everything off the barrel that I could in order to prevent even the smallest amount of barrel run out. Why take the chance on messing up an expensive barrel? I would treat it as if it were a brand new barrel and follow my way of achieving success. Just my thoughts !
Click to expand...
That is a lot of years of experience and knowledge. I have threaded over 100 barrels this way (barreled action minus bolt, trigger and scope mounts) thru the headstock and never ruined a barrel or skipped a thread. Are there other ways? Yes. Why am I up so late?!
 
As to the videos the world has a lot of them in it and more being born all the time . As we go through life hopefully we learn how to do things the way that works the best for us but that doesn't mean my way is the best way for you the end result is what matters not the way we got there . But if we aren't like the people in the videos we will be open to learning new ways that might just work better then what we are comfortable with doing at this time in our journey through life .
 
This jig was made to fit the chamber of my 308. The stock is removed and the jig fitted in the place of the bolt. Then to the lathe, the thick part in the chuck.
DSCF2395.JPG
to cut the threads.
The barrel was never removed from the action.
 
Well Blackhawk that is why your a tool and die makers and I'm a master gunsmith. I am sure you are a very good one with that many yrs of expierience. But why do you assume that I will use brass shims to hold the barrel in the headstock. I don't use shims in any setup I do. I also said that I made my own tools specifically for holding barrels in a chuck. I can tell you that my barrels don't move once indicated. I know this because I verify zero runout after cutting the tennon. Then again after cutting threads. I have not had any issues with runout. I can assure you I have never seen my lathe skip threads. Didn't even know a lathe in working order could skip threads. You know at the end of the day it's one of the simplest things I do is cut a thread for a brake. No hoopala simple. I've walked all my friends through doing it with no lathe expierience. I you feel compelled to take the barrel off go for it. Not to many real gunsmiths are going to waste their time and chance marring a finish to take it off. When I say real gunsmith I mean professional gunsmiths making a living building guns.
Shep
 
Pieter Willem Vorster said:
This jig was made to fit the chamber of my 308. The stock is removed and the jig fitted in the place of the bolt. Then to the lathe, the thick part in the chuck. View attachment 164003 to cut the threads.
The barrel was never removed from the action.
Click to expand...

Don't take this the wrong way but I would never put anything like that in my chamber. The possibility of damaging a chamber is way high and if you change to a softer material you lose rigidity. That doesn't even go into the fact that your losing a massive amount of rigidity by suspending a action on a small diameter rod 6, 7, 8" away from the chuck.
 
bigngreen said:
It just depends on the smiths set up.
Click to expand...
Agreed! Cutting corners at this stage may lead to problem when you thread on the suppressor. I removed a Browning muzzlebrake, threaded on my quick adapt Thunderbeast brake, and discovered the thread pattern was not square with the barrel. My suggestion is; never cut corners and trust your gunsmith. Alignment of the threads is in fact CRITICAL!
 
IdahoCTD said:
Threading is a slow RPM operation but turning the OD prior to threading really isn't. With HSS you can slow things down but carbide usually likes more RPM's. It's really hard to not have balance issues at high RPM's if the trigger and other things are left on the action. Remington's, and other fairly round receivers, do quite well at high RPM's if everything is removed though.
Click to expand...



Nathan , do you offer barrel threading now ?
 
As is said, there are more than one way to skin a cat. Doesn't matter how it gets skinned as long as the end result is still a skinned cat.
Like I said before, let the gun tell you what it needs and go with it. As long as the finished product is fit for purpose then what does it really matter.
Andrew
 
I never really skinned a how many ways are there really. If I did try how does one know if he did it right.
Shep
 
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