Newby question about barrels

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Bigtravoz
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Newby question about barrels

#1 Postby Bigtravoz » Fri Sep 08, 2017 6:39 pm

Are Douglas barrels any good and does anyone use them?

johnk
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Location: Brisbane

Re: Newby question about barrels

#2 Postby johnk » Fri Sep 08, 2017 8:29 pm

Haven't seen them around the traps (serious F or TR) for maybe 10 years.

Frank Green
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Re: Newby question about barrels

#3 Postby Frank Green » Thu Sep 14, 2017 12:54 am

Like Shilen and some of the other button barrel makers...Douglas has different grades of barrels. If you order one and want to try it get the top of the line. You pay more for it. The difference in the grades is primarily you are paying for bore and groove size uniformity.

If you want to build a inexpensive hunting rifle then it might not make a difference to you.

Again you pay for what you get.

Later, Frank
Bartlein Barrels

Bigtravoz
Posts: 26
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Re: Newby question about barrels

#4 Postby Bigtravoz » Tue Sep 26, 2017 8:15 pm

Frank Green wrote:Like Shilen and some of the other button barrel makers...Douglas has different grades of barrels. If you order one and want to try it get the top of the line. You pay more for it. The difference in the grades is primarily you are paying for bore and groove size uniformity.

If you want to build a inexpensive hunting rifle then it might not make a difference to you.

Again you pay for what you get.

Later, Frank
Bartlein Barrels


It seems that way with most things not just barrels and sometimes it seems that you pay top dollar and get a pile of scrap metal. I was interested as I had heard that a few years ago the new head of the company was a long range shooter and had improved the way they were doing things and that the quality and accuracy of their barrels had become very exceptional barrels but wanted to hear from those in the know.

Trav

Frank Green
Posts: 169
Joined: Wed May 28, 2014 11:48 pm

Re: Newby question about barrels

#5 Postby Frank Green » Wed Sep 27, 2017 12:02 am

Bigtravoz wrote:
Frank Green wrote:Like Shilen and some of the other button barrel makers...Douglas has different grades of barrels. If you order one and want to try it get the top of the line. You pay more for it. The difference in the grades is primarily you are paying for bore and groove size uniformity.

If you want to build a inexpensive hunting rifle then it might not make a difference to you.

Again you pay for what you get.

Later, Frank
Bartlein Barrels


It seems that way with most things not just barrels and sometimes it seems that you pay top dollar and get a pile of scrap metal. I was interested as I had heard that a few years ago the new head of the company was a long range shooter and had improved the way they were doing things and that the quality and accuracy of their barrels had become very exceptional barrels but wanted to hear from those in the know.

Trav


Trav, One of the guys at Douglas I talk to a couple of times a year. He gets a hold of me for a couple of donations to big match out near them. He has always been pleasant to deal with and we always have a nice conversation on the phone about guns and barrels of course.

Again like Shilen and some others who offer different grades of barrels you are paying for uniformity. I always tell guys the straighter the barrel blank, the more uniform the twist and the more stress free the barrel is along with the more uniform the bore and groove sizes are over the whole length of the barrel the more forgiving the barrel is going to be.

When you button rifle a barrel they have to do it as a blank. Then you have to restress relieve it. What no barrel maker can measure for is stress in the blank. Then when the button maker contours the barrel and other things like when the gunsmith cuts and crowns it.....any where in these machining processes if you hit a residual stress point it will cause the steel to relieve itself which causes the bore to open up/change. When this happens you cannot make it go back.

Later, Frank
Bartlein Barrels

Frank Green
Posts: 169
Joined: Wed May 28, 2014 11:48 pm

Re: Newby question about barrels

#6 Postby Frank Green » Thu Sep 28, 2017 2:09 am

Thinking about it a little more....I have actually seen button rifled barrels where they got them hot enough during shooting and they had a lot of residual stress in the blanks actually relieve themselves during firing. One barrel was a .22-250 improved on a prairie dog rifle and on top of the that the barrel was fluted which I don't recommend on a button rifled barrel either. Anyways the barrel had only been shot approx. 150 rounds and it relieved itself from the heat during shooting. The whole section where the barrel was fluted the bore and grooves opened up almost a full .001".

Later, Frank

Barry Davies
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Re: Newby question about barrels

#7 Postby Barry Davies » Thu Sep 28, 2017 7:28 am

Frank,
Are you saying that the blanks or steel billets for cut barrels are never stressed relieved either before or after machining.
Barry

Frank Green
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Re: Newby question about barrels

#8 Postby Frank Green » Sat Sep 30, 2017 12:52 pm

Barry, No I'm not saying that and if I understand your question correctly you are asking if cut rifled barrels ever get stress relieved etc....

Our steel starts out heat treated and double stress relieved as we get it from the mill. We don't induce any stress into the barrel blank and we don't do any stress relieving after rifling etc...

Hope that answers your question?

Later, Frank

Barry Davies
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Re: Newby question about barrels

#9 Postby Barry Davies » Sat Sep 30, 2017 7:18 pm

G'day Frank,
What about drilling and reaming prior to rifling would not that introduce stresses? I would have thought it would but then I am not a barrel maker.
Barry

Wal86
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Location: Kilmore, VIC

Re: Newby question about barrels

#10 Postby Wal86 » Sat Sep 30, 2017 7:37 pm

Frank Green wrote:Barry, No I'm not saying that and if I understand your question correctly you are asking if cut rifled barrels ever get stress relieved etc....

Our steel starts out heat treated and double stress relieved as we get it from the mill. We don't induce any stress into the barrel blank and we don't do any stress relieving after rifling etc...

Hope that answers your question?

Later, Frank


Frank

It is my understanding stress relieving is carried out on barrel blanks in order to minimise residual stresses in the barrel blank thereby reducing the risk of dimensional changes during further machining of the barrel..

Is it possible to induce stress in the cut rifle process/profiling/fluting/chambering process if so do you believe it to be beneficial in having the barrel stress relieved after chambering?

Ive seen a cut barrel where the bore diameter has increased by .0004" over the thread tenon where a muzzle brake was installed... muzzel was 1.050" dia with a .850" 28tpi brake... so minimal material was removed from the barrel... this suggest to me that residual stress was released and the bore has relaxed?
This bore measurement increased over a 5 month period before it stopped.. (.0007")
What are your thoughts?

Cheers

Alan

(I will not suggest the manufacturer of barrel as this would not be appropriate.)

Frank Green
Posts: 169
Joined: Wed May 28, 2014 11:48 pm

Re: Newby question about barrels

#11 Postby Frank Green » Sun Oct 01, 2017 11:40 pm

Barry Davies wrote:G'day Frank,
What about drilling and reaming prior to rifling would not that introduce stresses? I would have thought it would but then I am not a barrel maker.
Barry


G'day Barry, Drilling and reaming doesn't induce any stress into the blank. Reaming only takes out approx. .007" to .008" getting the barrel ready for prelapping and rifling. Your not doing a heavy cut etc...on it during this process or during cut rifling. During rifling we are only taking out approx. .0001" of a cut per pass in one groove at a time.

If there is any residual stress in the barrel blank we will see it during turning/contouring. The barrel will bow/bend on you. If this happens the barrel doesn't even make it to bore reaming etc...and we throw it away.

Button rifle makers cannot contour a barrel before reaming and rifling etc...

The one thing no barrel maker can measure for is any stress in the material. The only way to watch for it is during the manufacturing process.

Hope that answers your question?

Later, Frank

Frank Green
Posts: 169
Joined: Wed May 28, 2014 11:48 pm

Re: Newby question about barrels

#12 Postby Frank Green » Sun Oct 01, 2017 11:54 pm

Wal86 wrote:
Frank Green wrote:Barry, No I'm not saying that and if I understand your question correctly you are asking if cut rifled barrels ever get stress relieved etc....

Our steel starts out heat treated and double stress relieved as we get it from the mill. We don't induce any stress into the barrel blank and we don't do any stress relieving after rifling etc...

Hope that answers your question?

Later, Frank


Frank

It is my understanding stress relieving is carried out on barrel blanks in order to minimise residual stresses in the barrel blank thereby reducing the risk of dimensional changes during further machining of the barrel..

Is it possible to induce stress in the cut rifle process/profiling/fluting/chambering process if so do you believe it to be beneficial in having the barrel stress relieved after chambering?

Ive seen a cut barrel where the bore diameter has increased by .0004" over the thread tenon where a muzzle brake was installed... muzzel was 1.050" dia with a .850" 28tpi brake... so minimal material was removed from the barrel... this suggest to me that residual stress was released and the bore has relaxed?
This bore measurement increased over a 5 month period before it stopped.. (.0007")
What are your thoughts?

Cheers

Alan

(I will not suggest the manufacturer of barrel as this would not be appropriate.)


Hello Alan, I'll answer your questions in order of your post....

Stress relieving...as I said we get our material from the mill heat treated and double stress relieved. For our manufacturing process stress relieving it again won't guarantee us anything that it will help more. Again in my previous post (residual stress) is one thing no barrel maker can measure for regardless of the manufacturing method.

In a button rifled barrel. The blank has to be drilled and reamed before button rifling it. After it's button rifled then they have too (or should) restress relieve it again. This is because button rifling is a cold swaging operation basically and will work harden the bore as well as induce stress into the blank. Again there are no guarantee's that stress relieving the blank after rifling will remove any residual stresses.

I will say no that there is no way we induce any stress into the blank during rifling. We are only cutting on average .0001" per pass in one groove at a time. In some cases it's even less than that. So we don't induce any stress into the blank and the cut rifling process doesn't work harden the bore. Not work hardening the bore helps the barrel last longer as well.

I don't see chambering a barrel inducing any stress and causing problems. I myself have never seen it. On ammunition test barrels that we make the gov't in 5.56mm, 7.62mm and .50bmg we have to ball gauge the chambers with 10 different ball gauges. This includes two gauges that go up into the throat area. Also we have to gauge the bore and groove dimensions of the barrel every 1" for the inspection reports as well and I've never seen any changes.

Fluting: I would never flute a button barrel. I've never seen it effect a cut rifled barrel. Not saying it cannot happen but haven't seen it.

To your last comment about threading the muzzle and the bore opening up....Is it possible? I'll say yes. Then that would tell me the barrel had stress still in the blank. I again personally have not seen it happen. If it was ours I'd like to know about it and if it was ours I'd like to know the s/n if you have it? Let me know.

Any other questions let me know.

Later,Frank

Frank Green
Posts: 169
Joined: Wed May 28, 2014 11:48 pm

Re: Newby question about barrels

#13 Postby Frank Green » Mon Oct 02, 2017 3:43 am

Alan, Thinking about it some more and threading the muzzle. We did 4 ammunition test barrels in 7.62mm for Lake City about a year or so ago. The material started out at 2.280" diameter as we had to finish the breech end to 2". We had to thread the muzzles for 5/8-24 threads for suppressor attachments. The bore and grooves didn't change size. So I'd like more information if you have it on the one that changed on you.

Thanks, Frank

Gyro
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Location: New Zealand

Re: Newby question about barrels

#14 Postby Gyro » Mon Oct 02, 2017 5:27 am

It would seem from the information you're providing us with here Frank that "you can't trust the stress relieving the button rifling barrel makers are doing to the barrel after they've pulled the button through ?"

Because if the stress relieving operation the button barrel maker does after he has rifled the bore is thorough then isn't thier barrel now in the same state as the one that's just been cut rifled ?

Or does the button rifling process induce stresses that we can't trust can ever be removed ? I would consider this a fundamental question that needs to be properly researched ?

And re dimensional uniformity and straightness is a profiled and unfired cut rifled barrel any better than a button rifled one ?

Regards Rob

Gyro
Posts: 147
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Location: New Zealand

Re: Newby question about barrels

#15 Postby Gyro » Mon Oct 02, 2017 6:12 am

BTW Frank I don't wish to drag u into a cut Vs button debate. You have been good enough to provide a bunch of good information here. My current buttoned barrel seems to be going well such that when it doesn't i can be very sure it's me ! Regards Rob.


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