Barrel straightening

[30calflash]

I hope this is the place for some info. I purchased a Finnish Mosin m39 with a bent barrel some time ago. I know that barrels are straightend in the manufacturing process. I've heard of gunsmiths doing the repair also. The thought was that if I can't fix it it has a bunch of good parts. If anyone has info to pass along it would be appreciated. Thanks, Tom.

[John Traveler]

Rifle barrel straightening is not something that a casual hobbyist or even most professional gunshops can do effectively. Even the rifle barrel factories are "iffy" on their ability to straighten factory barrels. It requires a special overhead arbor press, a perfectly smooth light-reflecting bore, and an operator with many years of experience and ability. What chance does the average hobbyist or even most gunsmiths have in this effort?

[S.R.Custom]

This is one of those "depends" questions that only generates more questions... How bent is the barrel now? And how straight does it need to be after it's "fixed"? And it's also one of those things I can not offer any advice on unless I can physically examine the object.

But I can say this-- it is possible to take some bend out of a barrel with no more sophisticated set-up than two wood blocks and dead-blow hammer. And a Mosin would be the perfect piece to try your luck on.

[MBTcustom]

Hey can you get the barrel off the action? Id be willing to take a crack at it if its a last ditch effort. I would mount it in my lathe and use indicators to find the high spots. It aint nothin but a piece of 3/4" steel pipe. Bet I could get 'er pretty close.
I straitened a shotgun barrel once by building blocks up on my work bench and puttin the 'ol Arkansas on it. I lucked out and it came out great.
If your barrel is bent much, I cant imagine how I could make it worse and who knows? it might shoot fine. I will say this though, I would not go whacking it with a hammer; it was bent into its current shape and it must be bent back. Block it in with 2X4s on a solid workbench top and pull on it. That way you dont go to far and you cant put any thing in that you cant take out later.

[30calflash]

I sighted down the barrel from the action end and it has about 3" deflection down at the muzzle and about 4" left. It bent in front of the rear sight base. No kinks, dents or large dings that I could see. Looks like a shifter from a mid 40's pickup. Really.
I think it a longshot at best. What the Finn's enemies couldn't do to it the common carriers of the US did in the course of their everyday routine!
If I can get a couple pics I'll try to get them up.

[old turtle]

I think you might send it to Goodsteel and let him give it a try. His idea of checking it with a lathe sounds good to me. He is a machinist who seems to know what he is talking about. If all else fails you could get a used barrel I would think. But then, I am clueless in most things. I just saw your description of the damage and that is more than the usual bend. Might be new barrel time.

[rbertalotto]

I took a bunch of folks from my gun club to the Savage factory last year. Savage "trues" all their barrels with a very simple technic. You look through the bore at a white wall. It is amazing how easy it is to see the bend in the bore. Even if it is only a thousandth or two off. I was allowed to try my hand at straightening one. It was quite easy with the overhead press. I was told when they measure a bore with a laser device after this procedure, they were nearly perfect or as close as they could measure.

http://images53.fotki.com/v535/photos/2/36012/8646721/P1020126-vi.jpg

[rbertalotto]

BTW, that's not me........I'm much more handsome!

[frankenfab]

I took a bunch of folks from my gun club to the Savage factory last year. Savage "trues" all their barrels with a very simple technic. You look through the bore at a white wall. It is amazing how easy it is to see the bend in the bore. Even if it is only a thousandth or two off. I was allowed to try my hand at straightening one. It was quite easy with the overhead press. I was told when they measure a bore with a laser device after this procedure, they were nearly perfect or as close as they could measure.

http://images53.fotki.com/v535/photos/2/36012/8646721/P1020126-vi.jpg

That is very cool, thanks for sharing!

[30calflash]

That's the deal I've seen pics of at maybe Anschutz. There are a few things that I'll ponder before the attempt. I appreciate the replies thus far, including the offer to straighten it.
I think it would be difficult to remove the barrel at this time. Plus the added length of the receiver may help in the straightening and alignment of things. There is also a fair chance that it is bent under the sight base which would probably finish it as a repair deal. I'll get pics up this week. Thanks to all.

[John Taylor]

I have one of those inexpensive HF 12 ton presses that I use. Like the man said, look through the bore but on one with a 3" bend you ain't going to see through the bore. A couple of blocks with a half round cut out for support and another one to push with and they bend real easy. You need to go a little past center and let it spring back.

[JIMinPHX]

I spoke to a guy that had worked for Savage many years ago. The barrel straightening methods he described sounded crude at best. So did the standards for straightness that he said they employed at the time. He seemed to think that a barrel with a little bend was no big deal because as long as it shot to the same place every time, you could just adjust the sights to compensate for it. He said that back then, they only straightened the really bad ones. Rbertalotto's post makes it sound like they may have improved things since then. The one piece of valuable information that I did get off that gentleman was that they determined straightness by viewing the bore. Apparently the bore is not always concentric with the OD of the barrel, so indicating the OD is no guarantee of success.

I haven't straightened any barrels myself, but I have straightened plenty of motorcycle forks, pump shafts, impeller shafts & torque tubes. In most cases, you need 3 blocks that fit the OD of the part to be straightened & a hydraulic press with enough pressure to move the part. I concur with what John Taylor says about bending the part past straight & then bringing it back a little. If you don't do that, then you leave stress in the material & part of the bend will likely come back in time. As a rule of thumb, I usually bend most shafts & tubes about 5-10% of the original deflection past the point of being straight & then flip them over & bring them back straight.

[nanuk]

I remember reading an article by a gunsmith who straightened barrels, New and Used, using a press, for large bends, a lead hammer and lead blocks for smaller radius bends, and offset blocks and sliding the barrel in where you need, and pulling by hand on the end.

His theory was like JIMinPHX said. Barrels bend when shot anyways, as long as they are as stress free as you can make them and as straight as you can get them with the naked eye, they will shoot well.

I've never had a bent one to try, and hope I never do

[B R Shooter]

Most every MAJOR custom barrel maker will not straighten a barrel. It's not the barrel that is crooked, it's the drilled hole. You go bending the OD of the barrel to compensate for the drift in the drilled hole, then you WILL end up with a bent barrel.

A lot goes into the deep hole drilling. Of late, most barrel makers are doing a quite good job at drilling. When I put any new barrel through the headstock and dial it in, I look down the bore. At one time several years ago, it was not uncommon to see quite a bit of "wobble" in the bore while turning. No so often now days. Proper tooling of course plays a big part. But a drift in the drilling can also be caused by hard/soft parts in the steel. These barrels are after all an alloy, and the consistency can vary.

Another item on these so-called straightened barrels, I wonder if they are stress relieving them after they bend them?

[John Taylor]

I get barrels in from several different makers and some will have the bore running true to the OD and some will be off. Douglas barrels are always true because they turn the OD after it is bored to insure the bore is centered. Most barrels have the caliber marks on the end that is centered or where the drill started, this is used for the chamber end. If the muzzle end is off a little it does not matter because I turn between centers for a few passes to get the OD to match the bore. Very seldom will I see a bore that has a bend in the bore bad enough to see while looking through the bore on a new barrel. I get old rifles in with bent barrels quite often. Had one old 1886 come in that looked real bad, story was that great grand-pa used it to pry the wagon out of the mud. A lot of these old barrels are what we would call mild steel today, very soft and bend easy.

[Molly]

I once bought one of those $25 Chinese air rifles that arrived with a badly bent barrel. It would have cost nearly as much to send it back as it had cost to buy it, so I decided to try to straighten it out myself, since I couldn't do any harm. It sounds like you're in about the same boat, so you might want to give it a try. It's simple, easy, and won't cost you anything but the time.

Don't laugh, but I went out to the barn where I had a set of really heavy steps. I inserted the barrel between two of the steps, with the bent area down and closest to me. In other words, put the bend right at the edge of the step or whatever you use, and lean on it a little bit. Did this several times, until a little progress was evident. You can get a good idea of progress by noticing how far you bent it last time, and bending it just a TINY bit further next time. The trick is to make haste slowly. No point in getting rid of one bend by getting another one. Then I took it out and looked it over to judge the effect.

There was some visible improvement, so I did it again ... and again and again, until I couldn't see any bend left. Then I took it out and shot it a few times, which showed me that there was still a little bit of bend left. Back to the steps for few more LIGHT treatments and test groups. When I was done, it shot very nearly to the sights at about 20 feet, so I just moved the sights to zero it in the rest of the way.

Result: A well salvaged barrel that gave groups plenty good enough for tin cans and mice in the hay. It would never win any benchrest matches, but then, it never would have anyhow. Results were good, cost was zip, nothing expended but a little time, and I was well pleased with the outcome. If it works as well for you, good enough. If not, you haven't hurt yourself any, have you? Good luck, and let us know how it comes out.

[lreed]

I have a 95 Mauser that had a bend in the in the last foot or so in the barrel, would throw the bullet low and left, could not adjust sight to solve that, so tried streatening . A thin twenty-nine inch mauser barrel is like spring steel, used presses,lead hammers and got little results. In desperation used c-clamps and a little heat got the bore looking good,after fireing several rounds the barrel sort of went back home,crooked again,repeated the process again. but this time I hung the action on a beam tied a fifty pound weight to the muzzle, used a propane torch to heat to good sizzleing heat and let it cool slow. The bore is still streight and the rifle shoots cast with good accuracy. I will tell you up front this is a lot of doing with no guarrentee of success, worked for me but might not for you. Hope this helps. lreed

[JIMinPHX]

Near the end of WWII, the Germans made up a bunch of rifles with barrels that were bent almost like the letter U. They issued them to tankers so that they would be able to stick them through the top hatch & fend off an infantry attack without getting out of their armor box. I don't know how effective the guns were for their intended purpose, but all reports that I have heard have stated that they did shoot reliably. It sounds strange to me, but that's what I've been told. I've seen pictures of the rifles too.

[30calflash]

I once bought one of those $25 Chinese air rifles that arrived with a badly bent barrel. It would have cost nearly as much to send it back as it had cost to buy it, so I decided to try to straighten it out myself, since I couldn't do any harm. It sounds like you're in about the same boat, so you might want to give it a try. It's simple, easy, and won't cost you anything but the time.

Don't laugh, but I went out to the barn where I had a set of really heavy steps. I inserted the barrel between two of the steps, with the bent area down and closest to me. In other words, put the bend right at the edge of the step or whatever you use, and lean on it a little bit. Did this several times, until a little progress was evident. You can get a good idea of progress by noticing how far you bent it last time, and bending it just a TINY bit further next time. The trick is to make haste slowly. No point in getting rid of one bend by getting another one. Then I took it out and looked it over to judge the effect.

There was some visible improvement, so I did it again ... and again and again, until I couldn't see any bend left. Then I took it out and shot it a few times, which showed me that there was still a little bit of bend left. Back to the steps for few more LIGHT treatments and test groups. When I was done, it shot very nearly to the sights at about 20 feet, so I just moved the sights to zero it in the rest of the way.

Result: A well salvaged barrel that gave groups plenty good enough for tin cans and mice in the hay. It would never win any benchrest matches, but then, it never would have anyhow. Results were good, cost was zip, nothing expended but a little time, and I was well pleased with the outcome. If it works as well for you, good enough. If not, you haven't hurt yourself any, have you? Good luck, and let us know how it comes out.

I thought something along the same lines with possibly using a press if need be. Barrel steel is on the soft side from what I understand. I thought that once the process was underway and started getting close that a visual through the bore and maybe using a boresighter with the sights could give some indication of being close. Going slow and steady will be the WTG.
Again, thanks for all of your advise.

[jmh54738]

My thoughts regarding straightening would be the stress that results from the straightening process and how the straightened barrel will react to the heat of firing a string of shots. I believe that all barrels are stress relieved during manufacture. Ireed brings up interesting facts regarding straightening......As a tool and diemaker, sometimes a length of tool steel would warp in the heat-treat process beyond the amount of stock allowed for grinding. The young fellows tried using a press to straighten the steel with no affect. I was able to straighten the piece within .0005, that's half a thou, by setting up the piece on blocks (carbon/graphite blocks from the EDM) in a vertical mill and using the spindle to press the die section straight and without over bend. It was then slowly heated to around 450 or 500 deg F, (below the normal tempering temp) then allowed to cool. The .022" bend was reduced to .0005, and didn't warp again during finish grinding. As an example of stress in metal, just put a 6" long piece of cold rolled steel in the mill vise and mill off .062 from one side. Now check the once straight side opposite the cut and you will find it now bowed about .060 to .080 or more. Well, after all, it is cold rolled and full of stress.

[rbertalotto]

Proof is in the pudding...........Just look how accurate those Savage factory rifles are!

[B R Shooter]

Does Kreiger straighten their barrels? I think not.

[jmh54738]

Proof is in the pudding...........Just look how accurate those Savage factory rifles are!

What procedure does Savage use? Are the barrels straightened as a final step or are they straightened and then stress relieved? I thought that straightening was done before rifling so that the light reflecting through the bore could be used to determine the straightness or lack thereof. I just don't know

[rbertalotto]

The whole Savage thing is very weird.........and it doesn't make a bunch of sense to me or to most knowledgeable folks on boards such as this.........

The barrels are drilled, and then reamed, then button rifled on some VERY old P&W machines with a super secret cutting oil (this was the only thing during the whole tour they would not disclose)

Then they are contoured and stress relieved......From here they are straightened....As far as I know, no stress relief........They then go to chambering.

The amount of straightening is not noticeable to the naked eye from the external of the barrel. But it is VERY noticeable when looking down the bore.

I chamber all my barrels "through the headstock". Because of this method, I can look down the bore while the barrel is spinning. I've NEVER seen a straight bore. Not once........All bores from every manufacturer have curves in them. Obviously, most manufacturers care not about this curvature. Savage is convinced it is one more arrow in its quiver leading to their superb out of box accuracy.

[30calflash]

It looks like the only way to find out is to try it. Once it gets to the point of being straight the stress factor may kick in. I've read about rifles changing POI when they get hot. Maybe it takes a dozen rounds, a string of rapid fire or maybe 100's of rounds. These are barrels that were never bent, just factory rifles. If stress became a factor would a cryo treatment fix it? Or would the barrel 'bend' due to the treatment?
The idea of heating the barrel to a certain temperature seems like an iffy proposition. At least to me. But heat to some point is used in cryo processes, I believe.
Using a moderate cast load would probably help keep stress to a minimum versus shooting jacketed loads at high velocity.

[B R Shooter]

I've owned a Savage 110 single shot in 220 Swift. It did indeed shoot very well for a factory gun. And most of them do! But I'm not so sure the barrel is the key here. I looked down the bore of my Savage and it was awful! Not speaking of whether it was straight or not, the rifling and interior finish was rough to say the least. But the damn thing shot well.

I think the action and floating head has more to do with the accuracy than the barrel.

[leftiye]

I have a old Ruger that with the original barrel would place the first four in a line an inch apart horizontally, the next four in a line an inch apart vertically, and after that it would then shoot nice groups. I'd never seen anything that would wait for me to shoot the first eight shots, so I got a Titus barrel for it.

I would be very prone to thinking that if you bend a barrel it will stress the given barrel (almost by definition). Therefore it would seen smart to relieve it afterwards. The fly in the ointment is that when you relieve the stress, the bends come back! Kinda makes you wonder?

The bends that rbertalotto describes wwere probly put in by the gun drill. Also, button rifling makes a lot of new internal stresses in a barrel. It may be witch craft, but some manufacturers do produce accurate barrels, and wise people buy those brands - even if nobody can tell them exactly why those barrels shoot. Just think what hammer forging does to a piece of barrel steel (and then wonder why those barrels ever hit anything).

[uscra112]

Did he say that his barrel is bent THREE INCHES? Bending it back is going to leave some seriously fatigued steel, I would think. It's already stretched on the outside of the bend, and now you're going to stretch the other side by bending it back. It'll be an interesting experiment, but I don't want to be too close to it when it's fired.

Also, all steel has internal stresses in it from the rolling process. I worked for many years in the machine tool business, and saw time after time how a long part being ground straight on a big way grinder would "walk" all over the place, just from a few thousandths of an inch being licked off one side. Our guys had all sorts of strategies to mitigate this. It was a bit of a black art. Same thing for a barrel made from a steel bar - the drilling takes out metal that's under some non-uniform stress or other, and the remaining metal "springs" out of true in response. The best stress relief is age, but it takes years for most ferrous metals to stabilize. There was an artificial aging process that subjected the metal to strong vibrations for a period of days, and it did seem to work. I've never heard of it used on barrels, but it might be worth researching.

A trick some mechanics know for straightening a piece of steel wire is to stretch it. It would take a monstrous press, but I wonder if stretching a blank prior to drilling would do any good?

[eagle27]

I straightened a 270Win barrel once that had been accidentally slashed when the owner was cutting a track in the bush. The barrel was bent like a banana with a gouge of metal where the slasher blade hit.

I held the barrelled action between centres on my big old flat belt driven lathe and used the tool post to push the bend out of the barrel. I had to take it past centre near the end of the process to allow for spring back. Got it spinning true and sighting down the bore showed a perfect circle. Carefully hammered the gouged metal back into place (about half way along the barrel), reassembled the rifle, loaded up and put bullets down range. Perfect result and this particular rifle went on to shoot as accurate as it had always done and take many an animal along the way.

30calflash, it is worth a try if nothing else.

[mroliver77]

Here is a video of the process.
http://www.nij.gov/training/firearms-training/embed_swf.htm?link=images/videos.swf&flvLink=module04/images/fir_m04_t06_04.flv&slides=0

Personally I am not equipped with a press yet. If I had this p;roblem I would seek to either rebarrel or check with John Taylor on a price for his service. It might be cheaper than you think to send a stripped barreled action to and fro and get the work done.
Jay

[Multigunner]

I straightened a badly bent Remington .22 rf rifle barrel many years ago, by using a method I had used to straighten bent aluminum arrow shafts.

After roughly getting the worst out with a dead blow mallet I laid the barrel on a very flat slab of concrete then I first took a thick plank with a concrete block on top for weight and rolled the barrel back and forth till almost straight, then finished up rolling it with a slab of steel about 3/4" thick and 4" wide.


The British had originally carefully straightened all Enfield barrels, but when wartime shortages and lack of skilled hands cut into production they established that so long as the last six inches of the bore was straight the rifle should shoot straight. After that they used a six inch long gauge at the muzzle and only straightened a barrel ( or set it aside )if it didn't pass that gauge.

This is one reason that many sporterized No.4 rifles that have been shortened don't shoot so well as you might expect.

I've glad to see that Savage still honors the old methods. Most of my long guns are Savage products. Some like my 23B look a bit odd but they all shoot like precision instruments.

[oldmossback]

Resurrecting this old string I was wondering what I should do with my old barrel.
It is from a Win. 92 that I had relined and that gunsmith when stuffing the sleeve in the old barrel, bent my barrel, down between the rear sight slot and the under slot for the forarm screw.

He tried to straighten it but was not confident that it was straight.
I replaced the barrel and 30 years later I sold the gun but still have this barrel.

Recently reading over on the CAS forum I got the idea of building myself a 1873 from parts. The threads are the same for both rifles so I am considering using this barrel......maybe.
I like doing this sort of thing as I built up a Harley chopper about 35 years ago from scratch and have done a couple of other projects like this, including building a pistol from a kit.

After reading all the above comments concerning barrel straightening, I pulled this old barrel outta my closet.

How does one tell for sure the bore is straight? I tried the Savage method of using a white wall to view the bore, I do not see any curve or bulge. But the muzzle end is easier to see than the breach end so I reversed the barrel to peer down the muzzle and still it does not seem bent toward the breach end.

Now on the outside, I definitely can see ridges, wrinkles or ripples where the old outer barrel was bent and possibly wrinkled pushing in the sleeve. Running a metal straight edge I can feel the bulge around the slot where the forearm slot is. And can see it after several swipes of metal to metal.

However this is not all away around. The flats on the top side where the stampings are, is smooth. Just 3 or 4 of the flats on the underside have ridges or wrinkles.

So if your not asleep after all this, I have this question. IS this barrel worth saving? How do I determine if the sleeve is straight and has no bends? Or does this matter on the breach end?

Oldmossback

[RoyEllis]

Best way I know of personally to check for straightness inside, is to run a pc of strong yet flexible wire thru the bore and attach it to a stick or fiberglass rod so you end up with what looks like a primitive bow with the barrel around the string. Hold up to light and move the wire string around to different sides of the barrel. You'll quickly see any bent spots as the wire will touch on each side and leave a visible gap beneath at a low spot. Learned that trick from an old man I used to watch build black powder rifles when I was a kid. Sure wish I'd spent more time & learned all I could from him when I had the chance to do so.

[jblee10]

I think there is a great difference in straightening a newly manufactored barrel, and straightening a "bent barrel". A new barrel may have a slight curve. And I think a new barrel is straightened so it will shoot close to where the sights can be adjusted. I doubt that it makes much difference if the barrel is 100% straight or 98% straight. It just needs to be good enough to throw bullets under the sights, and throw them the same way each time. But a bent barrel is something else. I think a "tube" that is badly bent and then straightened will deform bullet and never throw bullets consistently. Just my thoughts. I could be way off target myself.

[Frank46]

I read an article where a guy rebent his M1 op rod using a workmate one of the folding tables. He made up some blocks and by adjusting them and cranking the two handles put the correct bends back in. The idea of heating a barrel is not really new. We had a rather big boiler explosion and the I beams behind the boiler were badly bent. What they did was wrap these ceramic blankets and apply current to them and get them to a certain temprature and hold the temp for some time. Then let them cool naturally. This had to be done a bunch of times to let the beams assume the position as when they were made. And last but not least lindsey books had a book that shows how the brits straightened barrels in WWI. Basically lead blocks and a hammer. Frank

[waksupi]

You can tell if a barrel is straight by looking at the light bars in the bore. If you don't know what it looks like, look at a shotgun barrel first, you will see the concentric rings the full length. Same thing in a rifle barrel, but with rifling grooves. If they wander to one side of the barrel, it is bent.
Barrel makers will straighten a barrel, before profiling.

[rbertalotto]

If the "gunsmith" used that much force to insert the liner that he deformed the barrel, I'd suggest the whole thing is a tomato stake. These liners should slide in with maybe a few light taps from a rubber mallet. No force is needed. If you are going to all the work of building a nice 1873, just buy a blank from Green Mountain or find another used barrel on E-Bay.

[DLCTEX]

20 or so years ago I watched a piece on TV about a barrel making company and they showed how the barrels were straightened. The man sighted through the barrel to find the bend and any bent ones were whacked over a lead anvil. The inertia straightened the barrel. I have since used the method to straighten rods and pipes, but never a gun barrel.

[oldred]

If you think about it a barrel actually does not have to be straight as long as the sights will align with the point of impact, the bullet will fly in a straight line (not accounting for drop) regardless of the path it takes to reach the muzzle. I am talking about minor curves/bends that a person might see by looking down the bore at a white background and not a gross bend that's obvious by looking at the outside of the barrel. With a badly bent barrel or one like oldmossback is describing I would be more concerned about bore concentricity than straightness, a slight bend or curve can still shoot very accurately (I doubt if many barrels are perfectly straight) but a spot in the barrel that's out-of-round or swelled/constricted will be very detrimental to accuracy. If a bullet is damaged by being squeezed through a tight or out-of-round spot in the bore it will not fit properly in the remaining length of the barrel it has to travel. If a barrel is bent very badly then it may be possible to get it straight BUT the bore is likely to be damaged, a tight bend over a small radius will likely result in a tight spot in that area after straightening. This tight spot will result in the bullet being too small to fit properly in the remaining section of the barrel which would likely result in poor accuracy.

[MBTcustom]

Just my 2 cents worth, based on observations in my shop and on my range.

Most factory barrels are not straight. This is a fact. Savage barrels however, (despite being quite liberal on groove and bore diameter, and chamber dimensions) are usually pretty strait. I do think this has a lot to do with their accuracy, at least for the first five shots, afterwards, they heat up and try to go back where they were before the straightening process.

Most after market barrel blanks are exceedingly straight. Less than .002 is very common regardless of what the outside of the barrel is doing. I can read light rings, and spinning the barrel in the lathe enhances the accuracy with which I can see the straightness.
There is a lot of bad information going around out there about how, even match grade barrels, are not drilled straight (coming from "smiths" that use rigid spiders to hold the barrels through the headstock of the lathe, and have no real grasp of accuracy, other than what they were told by another misinformed smith that does not understand either).
Even the cheap Adams and Bennett barrel blanks (Green mountain now) from midway average less than .002 TIR stem to stern.

A barrel is a very floppy thing, and easily influenced by the slightest pressure. However, in order to bend a barrel so that it takes a set, a pretty good amount of pressure is required. Steel doesn't take a set all the way through the pressure application. Up until the point where it will begin to take a set, it will spring right back to the original place with no effect whatsoever (Archers who shoot aluminum arrows know this very well). Once the barrel crosses that threshold, it's just a matter of pushing it exactly how much you need it to move and no more.

Have I straitened barrels? Certainly! Do I make a habit out of it? Absolutely not. I am of the opinion that there are so many good barrel makers out there, that life is too short to mess with crummy barrels.

Now, as to the effect that a bent barrel has on the trajectory of the boolit: Often, while a bent barrel is capable of extremely good consistency, it throws the projectile in a sort of helix that stabilizes down range. If you shoot on a good day with the sun at your back at long range, you can often see the boolit "spiraling" as it flies down range. However, at any given range, the shots will impact in nice little groups, which makes it so that most shooters never realize that the bend in the barrel throws the boolits in a helical pattern, kind of like an arrow with one feather missing.

[oldred]

Goodsteel, while machining a Green Mountain 1.270" round blank into the heavy octagon barrel for my High Wall I was amazed at the ease with which even a heavy barrel can be deflected. With about 3/4 of this 32" barrel extending past the steady rest on my lathe I had my dial indicator set up at the muzzle and by gently pushing with my finger tips I could get .020 to .030 deflection with almost no effort at all! It's no wonder the wood in a stock has such a profound effect on accuracy.

As far as barrels being bent what really matters is the sight alignment with the bullet trajectory, theoretically a barrel could be shaped like a pretzel and shoot straight if the sights were aligned with the path of trajectory after the bullet leaves the muzzle, but of course a large bend creates more problems that just sight alignment.

[MBTcustom]

Goodsteel, while machining a Green Mountain 1.270" round blank into the heavy octagon barrel for my High Wall I was amazed at the ease with which even a heavy barrel can be deflected. With about 3/4 of this 32" barrel extending past the steady rest on my lathe I had my dial indicator set up at the muzzle and by gently pushing with my finger tips I could get .020 to .030 deflection with almost no effort at all!

That's true old red. Now, set up a barrel in your steady rest spider only, so that it is rigid enough that you could machine it if it were attached to the chuck side spider. Now, run an indicator mounted in the chuck, and tell me how close you are to zero.
Huh? the spider itself wants to steer the barrel off center? you dont say?
Now observe how much pressure it takes to bring the other end of the barrel into alignment with the chuck.
Quite a bit of pressure is required in spite of the fact that your spider bolts are just barely snug enough to be rigid.
SO when you set a barrel up between two spiders, weather they are on iether side of the headstock, or on the steady rest, you are inducing longitudinal stresses into the barrel.
How likely do you think it is that the barrel is actually running strait?
It aint got a snowball's chance in hell.

That's why I spent a lot of time developing spiders that can be "aimed". When I set up a barrel in the lathe, the only way it could run truer, is if you put it in a zero gravity environment and give it a spin, and the straightness is preserved through the process of threading, chambering and crowning.

Because of this, I can tell if a barrel is truly straight. If I am working with a competition barrel, I send it back if I can detect any bend in the pipe.
that being said, it is not very common for me to find a straight barrel on any of the major manufacturers factory rifles.

[platinumtp]

I have a Winchester Model 1873 with a bent barrel. Will Savage repair it? If no, then who?

[oldred]

What are you calling "bent"? Is really bent to the point it can be seen? Is it REALLY bent as in a severe bend over a small radius?

[johnson1942]

just saw your post and want to do some input. many barrels are straightened. however the memory of the bend is in the steel. when the barrel heats up after a few rounds it starts to travel again toward the bend it has in its memory. impossibe to keep it from walking on the groups. however their is a cure. saw many a gun cured of walking groups with one 70 dollar cryo treatment. the steel looses the bent barrel memory when cryotreated. i use cryo plus on the internet, she is cheap and just as good as the others. after you straighten the barrel, cryo it. you could also sonic stress relieve it but that would cost much more. you would be surprised at how many factory over the counter guns have barrels made from straighted bent bar stock. thats why some well made factory guns wont shoot for ****. a simple cryo treatment cures it.

[bannor]

that is great to know, man. I've always just assumed that a bent barrel was scrap metal.

[johnson1942]

i had a friend years ago who lived 1/2 mile south of the canadian border in the heavy woods. all his red meat came from the wildlife their. he bought a 300 weatherby mag. it would hit dead center the first shot then walk right off the target at 200 yards. it drove him nuts. it was a well made gun with a well made barrel but the barrel had the memory of a bent bar stock before becomeing a well made barrel. after he cryo/d the barrel it shot dead center at 200 yards, round after round their after. it took the memory of the bend out and is now a very special gun. the steel in a cryo/d barrel will last longer then one that isnt also. we never chronographed his loads but usually they shoot faster after cryoing as the steel is slicker or the carbon in it is. the barrel harmonics become a lot more quieter and consistant in a tighter circle on the muzzle after cryoing also. its a win win thing to do.

[Multigunner]

Something I remember from a thread on 1903 replacement barrels.
Some of the barrels turned out to have been demilled by bending before being sold off as scrap metal.
Someone bought up a bunch of these barrels and straightened them then sold them as NOS without alerting buyers to the salvage methods.

The barrels appear to have been reasonably serviceable, but when they had straightened the bend the method they used caused the bore to oval at the point of the bend. This would not be a favorable condition.

[DeanWinchester]

The last machine shop I worked in had a hydraulic press specially made for straightening lead screws and linear guides. It had a dial indicator and you could adjust the stroke by as little as a half thousandth. In the hands of an experienced operator it was very good at straightening anything. I straightened a Garand op rod on it while worked there. Wasn't exactly National Match quality but the rifle ran fine after I straightened the part that was bent.

It CAN be done but as said before it ain't for any ole body.

Hey Goodsteel, if your lathe is big enough; I've straightened tubing on a LeBlonde Makino lathe years ago by finding the high spot and using the tool post to put pressure on the high spot. (NOT WHILE ITS RUNNING OBVIOUSLY). Use an end mill to cut an appropriate radius in a piece of square stock and put it in the tool post. You need a very sturdy carriage to do this though.

[country gent]

Federal made a bed with 2 centers ( think 2 tailstocks) and a screw press that was adjustable its length of the bed. It was very solid casting on the bed and ways were ground for accuracy. An indicator on stand could be positioned on bed on unders side of the srew press. and these were made for straightening bars and or tubes. With the fine acme thread and big hand wheel a lot of controlled force could be applied to straighten a part. I believe there was a set of tailstocks with vee blocks instead of spindles/centers also. We used them to straighten work before od grinding. Looking thru a barrel at a distant cross wire can give a good idea of how straight and or true the bore is. A bore that isnt straight or bent appears oval when looking thru it at the cross. It dosnt show internall stresses in the stock. I believe that is why a rifle may perform better with age and or time, As metal ages stresses are relieved naturally from temperature changes and atmosperic changes. Cruro speeds these changes up as does the sonic stress relief. We had a "super freezer" at the last shop I worked (60* below zero) when making some gages or tooling ( vee blocks, angle plates, straight edges) we would give a weeks cycling of out of freezer when you came in into freezer before going home for 5-7 days. It helped to relieve stress and made grinding into tight tolerences easier. Krigers barrel stock is cryroed before starting to ease machining I was told.