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A question about bending barrels. Login/Join 
Freethinker
Picture of sigfreund
posted
This will probably result in a lot of strained eyeballs from being rolled up in disbelief, but perhaps not, and that’s why I’m asking.

Is there any reasonable likelihood that a rifle barrel would be bent permanently, even if only very slightly, if the rifle were stored with lateral pressure on the barrel? An extreme example would be if the rifle was in a horizontal display rack that supported it only at the stock and on the barrel near the muzzle.

A ridiculous question, or an actual concern? (And if the former, I don’t need to be reminded that barrels are made of steel, not silly putty. Wink )




6.4/93.6

“Wise men talk because they have something to say; fools, because they have to say something.”
— Plato
 
Posts: 47365 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
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If a fat chick fell on it or tried to do pull ups on it when in the horizontal display rack, could be bent.

FYI. ALL barrels/bores have a curve to them. Curve of .030 over 26" is not too extreme. Important to "clock" that curve at 12:00.
 
Posts: 3197 | Location: 9860 ft above sea level Colorado | Registered: December 31, 2008Reply With QuoteReport This Post
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In my extensive testing of various barrels that had been stored in different positions, I found that the effects of the earths gravity on a well formed rifle barrel where slightly more than than the effects of other planetary bodies in our solar system on actual rifle performance. I continue to test this regularly by storing rifles in various positions but still feel like there is much more testing required. Perhaps parties interested in the results would be willing to support my testing by sending me reloading components or funds to support this vital research?
 
Posts: 1788 | Location: Spokane, WA | Registered: June 23, 2008Reply With QuoteReport This Post
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Picture of maladat
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No chance at all.

At any storage temperature that doesn't destroy everything else on the gun, steel will not deform over time from small forces.
 
Posts: 6319 | Location: CA | Registered: January 24, 2011Reply With QuoteReport This Post
Freethinker
Picture of sigfreund
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quote:
Originally posted by offgrid:
FYI. ALL barrels/bores have a curve to them. Curve of .030 over 26" is not too extreme. Important to "clock" that curve at 12:00.


Now, see: That tidbit of information was worth any reactions I might get from the clever crowd. Big Grin

But it raises another (unrelated) question. I have enough trouble indexing muzzle devices to more or less the angle I want them. Any times for getting a precision barrel clocked correctly?

And thanks to you and maladat for setting my mind at ease. Smile




6.4/93.6

“Wise men talk because they have something to say; fools, because they have to say something.”
— Plato
 
Posts: 47365 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
Buy that Classic SIG in All Stainless,
No rail wear will be painless.
Picture of cee_Kamp
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This thread brought back memories for me.
My Dad purchased a used Mossberg bolt action 12 gauge shotgun for me when I got to legal hunting age. It had a Poly Choke installed.
I couldn't hit worth a damn with it.
Eventually, it went to the gunsmith and had the Poly Choke removed, the barrel shortened, and Williams front bead on a base / rear blade sights installed. (slug gun for deer)

After all the gunsmith work I took it to the range and at 50 yards, it hit THREE to FOUR FEET to the right using slugs.

Moving the rear sight to it's adjustment limits moved it closer to center, but not enough for it to be effective for deer hunting.

I brought it home, centered the rear sight and removed the barreled action from the stock.
I made a wood block with a hole bored in it that matched the outside diameter of the barrel near the muzzle and then sawed the wood block in half.

Next, the barreled action got clamped in a large bench vise using the block of wood near the muzzle.

It took every bit of strength I had to bend that barrel to the left, and that's using the receiver and barrel length as a "cheater" bar.

The bend to the left was visible to the naked eye.

Further investigation using a pin micrometer showed the shotgun barrel bore was not concentric with the barrel outside diameter.

Further testing at the range proved the gun shot well for deer hunting with slugs.

I eventually sold the Mossberg to someone at work that wanted an inexpensive shotgun.
I asked him to shoot it and make sure it was what he wanted before he paid me.
He was happy and I got the cash.

I haven't owned another Mossberg since and it's now approaching 48 years.

So sigfreund, Do not be concerned whatsoever about storage conditions causing a barrel to bend...



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Posts: 1497 | Registered: December 14, 2009Reply With QuoteReport This Post
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Like anything it is certainly is possible to bend a rifle barrel, but as was said its never going to happen in a display rack.
Heck the US Army M16 TM has a gauge to check the straightness of M16 barrels in the special tools.
I see surplus ones available if you have an AR. Of course the tool is like 3x the price of a new barrel.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
 
Posts: 10966 | Registered: October 14, 2004Reply With QuoteReport This Post
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The simple answer to the original question is NO.

Steel has some wonderful properties in regards to strength and durability that many other metals do not have. One is that Steel will NOT deform plasticly until the Yield Stength has been exceeded. Basically, until you get to the Yield limit the steel will spring back to it's original state.


I've stopped counting.
 
Posts: 5621 | Location: Michigan | Registered: November 07, 2008Reply With QuoteReport This Post
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Picture of maladat
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quote:
Originally posted by Scooter123:
The simple answer to the original question is NO.

Steel has some wonderful properties in regards to strength and durability that many other metals do not have. One is that Steel will NOT deform plasticly until the Yield Stength has been exceeded. Basically, until you get to the Yield limit the steel will spring back to it's original state.


This is not completely true, you can also get permanent deformation from fatigue (repeated cyclical loading that stays below the yield strength) or creep (slow deformation resulting from below-yield-strength loads at high temperature).

Neither is really relevant here, though.

If you stored your rifle at, say, 1,500 degrees Fahrenheit (still well below the melting point of steel) the barrel might very, very slowly develop a bend from the lateral force imparted by the rack. That doesn't happen in steel at room temperature, though.
 
Posts: 6319 | Location: CA | Registered: January 24, 2011Reply With QuoteReport This Post
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If the action is glass bedded in the stock,I could see it creating some problems with the bedding,perhaps.


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Posts: 12575 | Registered: January 17, 2011Reply With QuoteReport This Post
Freethinker
Picture of sigfreund
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quote:
Originally posted by maladat:
creep (slow deformation ...).


That was something I was thinking of when I pondered the question. Despite the fact that steel structures have existed for decades (centuries?) without exhibiting any visible change, I was reminded of the belief that even glass can “creep” over long periods. That’s something that has supposedly been observed in the windows of very old cathedrals. And yes, I do recognize that the time periods are much different and that rifle barrels aren’t made of glass any more than silly putty, but it’s the sort of thing that gets me thinking and wondering. I therefore appreciate the informative comments.




6.4/93.6

“Wise men talk because they have something to say; fools, because they have to say something.”
— Plato
 
Posts: 47365 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
Like a party
in your pants
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Interesting way to straighten a barrel.
https://www.youtube.com/watch?v=VB1KfwffqHM
 
Posts: 4609 | Location: Chicago, IL, USA: | Registered: November 17, 2002Reply With QuoteReport This Post
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sigfreund...worry not...I keep a list of possible topics to post for future discussions, topics that I like to mull on and do a little research on, before posting. On my list was this very topic.

My thinking reasoning brain would tell me not to worry about the steel barrels of my rifles bending or drooping over while sitting stationary...but my curious Cro-Magnon/ Lizard brain would look at those barrels and start to wonder...thank you for starting the topic.

Interesting to learn that all barrels have a curve to them though!
 
Posts: 7324 | Location: the Centennial state | Registered: August 21, 2006Reply With QuoteReport This Post
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Barrel steel should have enough elasticity that the minimal deflection from being in a rack should go away once the rifle is moved from the rack. But I wonder -- it doesn't take much weight to bend a barrel and change POI.

In one precision rifle course we tested the POI effects of resting our barrels on a support wire. I used a 308 in this course, with a pretty thick Bartlein M24 contour barrel. The two tests involved resting the barrel just forward of the end of the stock, and at the very end of the barrel. Given that I supported the rear of the rifle with my shoulder, in theory only the front half of the rifle -- and half of the rifle's weight -- was resting on the wire and bending the barrel upwards. Anyway for my rifle, POI moved up 1 MOA while touching the wire just forward of the stock, and POI moved up 2 MOA while touching the wire near the front end of the barrel.

Now if for whatever reason the steel barrel didn't return to its original shape, in theory POI could change slightly.

I doubt that storing a rifle in such manner makes a difference, however.
 
Posts: 7852 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
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There is no chance of bending a barrel in a permanent way with storage on a rack (if as maladat says human tolerable temperatures are involved). If the stress involved are below the yield strength, when the stress is removed there is no permanent deformation. That's simply the way it is. Since this thread kept popping up I bothered to look up the numbers for 416 which I know is sometimes used in barrels ( and I know a lot about from using it in the marine industry) and that number is really big. I didn't look up the bending numbers to see about Fritz wire testing since I really don't know a good way to find that in the data I have which is about solid shafts.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
 
Posts: 10966 | Registered: October 14, 2004Reply With QuoteReport This Post
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I thought you were going to ask about these...

https://www.popularmechanics.c...wwii-curve-a-bullet/


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Posts: 6309 | Location: In transit | Registered: February 19, 2013Reply With QuoteReport This Post
Certified All Positions
Picture of arcwelder
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quote:
Originally posted by Scooter123:
The simple answer to the original question is NO.

Steel has some wonderful properties in regards to strength and durability that many other metals do not have. One is that Steel will NOT deform plasticly until the Yield Stength has been exceeded. Basically, until you get to the Yield limit the steel will spring back to it's original state.


Everything has a modulus of elasticity. Not just steel. Not just all metals, everything. I think you're talking about the Yield Limit, and again, every material has a point beyond which it will bend without returning to its original shape.

The simple answer to his question is no.

If the answer were yes, we would not use steel for all the things we use it for.


Arc.
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Posts: 27000 | Location: On fire, off the shoulder of Orion | Registered: June 09, 2004Reply With QuoteReport This Post
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Just a note on a sort of related topic.

While simple storage of a longarm leaning in some way isn't going to bend the barrel, single barrel shotgun barrels are relatively easily bent and this can be used to advantage.

I have hole in one of my anvil stumps I use for zeroing shotguns. It is quite easy to do if one gets the hang of it. Many are the shotguns that do not shoot/pattern on the bead/rib/sights. Tweaking them in the direction you want the shot to go makes the shot go in the direction you tweaked!

Here's an example:


Amount tweaked:



The "fixture":



In use:



The Results:

40 meters {43 yards} and a handloaded round of buckshot.



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Posts: 5059 | Location: Idaho, USA | Registered: May 20, 2005Reply With QuoteReport This Post
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