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10-15-2011, 06:00 AM #1
Threading barrels, any other way?
GOOD MORNING LEARNED ONES,
i HOPE SOME OR ONE OF YOU GUYS CAN GIVE ME AN ANSWER ON THIS.
I OWN SEVERAL ASS'T FIREARMS WITH THREADED BARRELS, AND THAT IS HOW I ORDERED OR BOUGHT THEM!
The pistols are cheaper to buy w/ threaded already as opposed doing it later as an afterthought ,As we all know.
Rifle barrels DEFINITELY,I have a small, but adequate workshop building (24'x20') , and it serves me well as it is, (I will post photos at a later date)
like all of you over the years you acquire more ,better tools and parts, some we have to make custom because of availability,or originality, especially custom projects.
Most of my power tools are of good quality not expensive some,others yes.
they are all well maintained and cleaned or sharpened regularly,but about 50% of my work can be done with the right "Dremel" attachment as I am and have been hooked on Dremel since my grandfather"s apprentice days with me!
I was a good learner from the best teacher a young boy was lucky enough to know.
THE ONLY MACHINE I DO NOT YET OWN IS A SMALL LATHEIt is possible to fit one in my shop, but for years I have gotten along without one,so my question, can decent barrel threading be done without one?
Thank You for any qualified reply, Sincerely ,Eric,P12
p.s. bear in mind oopah never gave me my graduation sheepskin!
10-15-2011, 10:12 AM #2
Well threads can be cut with dies but its very hard to get the threads straight. Borderline next to impossible. I suppose if you were really hard pressed you could do it as it was done in some old blacksmith shops and lay out the treads with a thread and ruler and cut them with a three cornered file. Actually don't even consider any of the things I have just said I was just rambling. You have plenty of room for a small 18 inch hobby lathe for pins and screws and a 14 x 40 back gear lathe for barrel work. There should be boat loads of them floating around in your neck of the woods. Any place you find farms or communities with small machine shops you generally find equipment like this.
10-15-2011, 12:04 PM #3
What about an add on piece that is where the i.d. of the add on is the same size as the o.d. of the rifle barrel, and the add on is threaded where i need it 1/2x28" (I'm probably the only person I know who hates the metric system,I'm well known for being opposite since my S.F. days),so does that sound practical? Silver solder or braze the sleeve on , the end of the sleeve is threaded from some dist.
now who sells such a thing?
10-17-2011, 09:56 AM #4
Cutting threads on a barrel needs to be done well.
The provide the shear strenght to keep the barrel attached to the reciever and they provide the clamp force to keep the barrel from moving relitive to the reciever.
Threading a barrel is a bit more involved than simply adding the v shaped helix. It usualy involves not only adding threads, but a thread relief cut and a shoulder for the barrel to snug up against. All of these features are normaly concentric with the bore and some effort is taken to insure this. This type of work is what a lathe excells at like no other tool.
So, assuming you are SOL on the lathe, what should you do ...... buy a lathe.
The big issue with threads is getting the proper form and getting them square to the barrel. Proper form will require a precision cutting tool, like a die. Yes old muzzle loaders do have hand filed threads on the breach plugs, but they work a rather low pressures and the breach plug does not provide alignment between a barrel and reciever.
Conventional dies are notoriously bad about starting out of square. Even with a pilot to start on that is the same OD as the ID of the die is no garentee they wont walk away.
The old fashoned variable dies with moving cutting jaws might do a bit better job of staying square. You can start them wide open and clamp on the od of the part and slowly adjust them to work the thread in a little bit at a time. This will give you a higher probability of getting the thread square to the OD of the barrel, but not necessarily concentric to the bore. You will need to have the mating thread made and check fit it reguarly to avoid overcutting the barrel.
Clamp shoulders will probably require a lathe, or a system like Savage uses with a secondary nut to provide the clamp surface.
At the end of the day you will probably be time and money ahead to add a lathe to the tool collection.
10-17-2011, 08:09 PM #5
10-18-2011, 05:02 AM #6
HOW ABOUT THIS ONE ?
I have been all over the world , literally looking and asking , all you guys are right, I should have done this years ago!
The money I've spent on having some machining done , because I only had one shot at it , and did not want to shit it all up.
Like i said I am not afraid to say I am an Apprentice still, but some day?
I understand that most of these new one's are electronically set as far as tpi./ gauge etc..
10-18-2011, 07:20 AM #7
Scanning this forum and others will revieal that most gunsmiths still use modest size manual machines with old school manual threading systems.
Most of us are small shops with limited budjets and either have second engine lathes from trade schools and small job shops or new machines imported from Asia.
CNC machines have not yet reached the price point to enter very small shop market and when a second hand computer controled lathe winds up on the second hand market, its either grabed by a small job shop or so clapped out that the scrappers are the only ones who want it.
CNC is an interesting animal. It requres a whole new set of skills to diagnose and repair the machine, and the components that go wrong are not the types of things most of us can fix in our garage. After 20 years or so of service, many of the electronic parts are obsolete or unobtainable. This can make repairs very expensive. Often the only other options are retrofit of the entire control system or junk the machine. These factors reduce their popularity on the second hand market, and rightly so.
If your getting into the market for a lathe, a manual maching course at the local trade school would be an excelent investment. You will learn how to operate the machine correctly and get a good feal for how much machine you realy need. Learning and breaking tools on someone elses machine will save a lot of frustration and expense when you get your own machine. The instructors will also have some feal for the local market becasue they will know the shops in the area and a lot of the local machinests. They will probaby be able to send you off in the right direction on your quest to find a machine.
10-18-2011, 12:50 PM #8
Thank you for the reasoning, but the small jobs such as threading a barrel , or boring a barrel with high precision ,etc. are easy enough to learn as you get familiar with any machine, besides this one is only one of several i have looked at.
I have a small background in electronics so it should not be to difficult to get used to a new one , besides where I live there are not a lot of schools or machine shops that i can afford to wait around for till they decide to replace their older ones , when i was in school i can remember breaking a thing or two also , so why take a chance on someone's used machine or a motorcar for that matter.
The prices are not that high either ( between 600.00 and 1,000.00 Euro's)
i'll probably spend as much or better repairing a used one.
11-03-2011, 04:45 AM #9
11-03-2011, 06:55 PM #10
A lathe for barrel work needs to have a minimum of a 1" hole through the headstock, so about the smallest that will work is a 12X30. Smaller ones are great for small work, just not barrels.
11-03-2011, 10:08 PM #11
You don't need a 1" through hole on a lathe, but if you don't you will need a long bed so the entire barrel plus the tailstock and various tooling all have enough space. I have a 5' long bed and sometimes I start to get very short on space for a rifle barrel, especially when chambering.
I would disagree about needing a lathe to do "safe" threading work. If you cut the threads well with a die then they should be safe, i.e. not let the barrel separate from the receiver. But you will probably end up with the barrel going into the receiver crooked which will cause all kinds of problems that you don't want to have.
Why not do a pressed fit barrel with a pin, works for AK47's and many other firearms. Though it would be tough to get things to a press fit without a lathe.
Or you could get things to a looser fit and solder or braze the barrel to the receiver. I have a 357 mag rifle that I soldered the barrel into a sleeve that is screwed into the receiver works very well. (I did this because the old action had a very big barrel thread, so I bored out the old barrel and sleeved in my new 357 barrel and soldered it into the old barrel, ~3" stub of barrel was used)
Though honestly it is really hard to do this kind of work without a lathe, you should be looking for one. Alignment will always be an issue. I could do without many power tools in my shop (though they would take a hell of a lot longer), but my lathe does some jobs that are very hard duplicate any other way.
12-01-2011, 02:44 PM #12
Here is a good tutorial for barreling/chambering
from German Salazars blog. Not saying it's the best or only way but it is well presented, and photographically documented. German writes very thorough technical articles.
The Rifleman's Journal: The Voyeur's Guide to Barrel Chambering - Part 1
12-08-2011, 03:53 PM #13
As a follow up German has now topped the
AZ State Long Range FTR Championship
AZ State Palma FTR Championship
with this barrel. It is great to see something I did shoot that well. Much of it goes to the shooter's skills. It was fun to be a part of the experiment in showing the steps to chamber a barrel and not to say any ones method is better or worse.
12-08-2011, 04:34 PM #14
So when indicating the breech in with co-ax indicator, how did you know that the indicator was on center? And if it is perfectly centered, why does the reamer need a pilot and a floating holder? And how many barrels could Speerchucker chamber while we read these 5 whatever-they-ares?
12-08-2011, 05:18 PM #15
the barrel is what is turning, not the coaxial indicator. why he is using that style indicator, i have no idea. it looks like it's mounted to a qc tool holder. either way, he's using it like a standard dti though. the reason for a floating holder is because most people have a hard time keeping a tail stock dead nuts centered over it's entire travel in all temperatures.
edit: i didn't realize the john in the linked article was jkl that posted earlier. i guess he can answer your concerns himself.
12-08-2011, 05:37 PM #16
12-08-2011, 05:51 PM #17
the co-ax indicator doesn't need to be centered. it doesn't matter if it is not centered as long the od of the bore is within it's range. the rear of the indicator is NOT turning, the barrel bore is.
i explained why most people use a floating reamer holder. i am not so sure you even need a pilot bushing, especially once you have the neck portion stated in the bore. if you could have the reamer dead nuts parallel to the bore and say that way throughout it's travel, i don't think you would need a floating holder or a pilot bushing. the problem isn't how the bore is being setup, it is how the reamer is pushed.
12-08-2011, 06:12 PM #18
for shits 'n grins, the other day i chucked up the non-tapered portion chamber end of a quality barrel blank. using my 4 jaw chuck i dialed it in until my .0001" mitutoyo indicator had no visible movement about 2 inches into the bore. at about 4 inches into the bore i indicated .001" of runout. i moved back to the 2 inch point and had no visible movement on the indicator.
that got me thinking maybe my chuck jaws weren't all that parallel since i haven't checked them in a while. i chucked up a piece of 1-1/4 inch bar and made a skim pass a few inches long. i flipped that bar around and dialed it in until i had no visible movement on my .0001" indicator. i moved the indicator to the end of the skim cut and still had no visible movement. i guess my chuck jaws are pretty parallel.
the point is, if i chucked up a barrel and didn't worry about trying to center the bore over the portion i was working on, with a rigid holder the reamer is going to be forced to flex to follow the bore. sure, it would only need to flex about a thousandth. but when you are trying to get the absolute most accuracy out of something, why have the reamer trying to overcome any other forces besides the radial cutting loads?
if the bullet followed that .001" over two inch trend at a muzzle, that could lead to a baffle strike on a long muzzle device only .020" over bullet diameter. even without a baffle strike, it's not something that i would consider beneficial to accuracy.
12-08-2011, 06:42 PM #19
I have steared away from threading barrels because I was told that you have to be dead on center with the barrel because the bullet may hit the front exit hole on the silencer or supressor and deflect. How accurate does threading have to be in relation to the bore?
12-08-2011, 07:37 PM #20
The need for axial alignment between the bore and threads is heavily influenced by the tightness of the suppressor bore. If you are using a 30 cal suppressor on a 223 then you can be off more than if the same suppressor is on a 30 cal.
But as it was pointed out even coming close to hitting a baffle in the suppressor is not an ideal thing and will likely degrade accuracy.
Sorry I can't give you a cut and dry answer. You can work out the numbers, bore size of suppressor - dia. of bullet divided by two (I assume the end of the barrel and the suppressor are staring out aligned, perhaps a bad assumption). Take that number and the length of the suppressor and you know how out of alignment things can before before you start to get baffle strikes.