Hi all,
I have a military surplus rifle in 22lr with a bent barrel. It is bent a total of about .125" in a long arc about 14 inches long starting about 10 inches from the receiver. I have the barrel off and believe I can take a shop press and get it close enough by eyeing the bore as I apply pressure. I have seen this done by barrel manufacturers but they have special jigs to hold the barrel and a large handwheel press. I am going to make 3 inserts matching the barrel contour, one for the start of the bent area, one for the middle of the bend shifted just a bit toward the muzzle, and of course one matching the end of the barrel. The middle will be used to press against with the arbor and of course the two ends will be statically held. Other than carefully lining up the bend 180 degrees to the arbor and going slow any thoughts? thanks

Many years ago I was given a barreled action with a bent barrel. The owner assumed it was ruined so he gave it to me for parts. Rifling was like new so I thought I would try to straighten it. Used V blocks in a hydraulic press with some brass shim stock. Used a mag base dial indicator to locate the high spot.I found I had to press the barrel back a little past straight because the barrel would spring back when the pressure on the ram was released..Small steps are best. Turned out that barrel shoots better than some I have that were never bent.

I have used several methods to straighten barrels. From a purpose made straightening press, to a brisk whack against a stump and all worked out ok though some were better than others.
Two blocks of wood on the bench and a Bessey clamp worked as well as any.
There are limits, of course. If the barrel is bent sharply enough so that the bore is not round, it is unlikely that straightening will be successful and I would usually not even try. A long, gradual curve could be easily handled though and always worked out OK. Slug the barrel after straightening to guage bore shape. Regards, Bill

many years ago at the coot factory i watched the old craftsmen working overthe famous hand fitted pythons.figured i would see big microed handwheels and all sorts of special equipment. instead i was vices, 2x4;s pipes etc. the special part was all in the skill of those old guys

quote:

Originally posted by butchloc:
many years ago at the coot factory i watched the old craftsmen working overthe famous hand fitted pythons.figured i would see big microed handwheels and all sorts of special equipment. instead i was vices, 2x4;s pipes etc. the special part was all in the skill of those old guys

Darrel Enzenauer liked to tell a story about old guys with skills. The nose cone of a nuclear submarine came out a little screwy once, a lot of money on the line. One old coot spent an afternoon with his torch heating up some judiciously selected spots and got the surface back in specification. Saved a ton of time and money.

I have a cheap hydraulic press in my shop for that type of job. A few years back I had a CETME in the shop that shot several feet to the left at 50-yards, making it useless. I really didn’t want the job but the customer was a friend so I said I’d try. I spent a lot of time thinking about it, and finally decided to just bend the barrel. Using my laser boresighter to guide me, I supported the barrel with V-blocks and bent the barrel until the boresighter lined up with the sights. Took only a few minutes and customer was happy to have a serviceable rifle.

A 25 lb bag of shot on the bench..Just whack the barrel down on the shot bag to straighten...A spare tire (inflated) works the same..neither mars the barrel.

I was told in gunsmithing school that whacking the barrel against something like a tree, tire, or bag of shot, etc. is somehow better than slowly straightening it with a press. Not sure if this is a metallurgical fact, but PO Ackley started the gunsmithing department in Trinidad and he graduated magna cum laude and was a college professor of metallurgy. Maybe the whackin method was handed down from his time teaching at TSJC.

Here is how one guy does it. Never tried it myself.
Barrel Straightening

The early barrel makers for BSA in England straightened barrels by wacking over a lead block and sighting down the barrel until they got a perfect circle by eye. Apparently they were experts at it.
I've straightened a Sako 270 Win barrel that had a quite pronounced banana bend in it after the owner leaned it against a small fern trunk while he carried on clearing a track with a slasher (machete blade on a long two handed handle). On returning to the start of the track he slashed the fern trunk forgetting his rifle was leaning against the trunch on the other side.

I carefully peened the small 'slash' of metal back into the barrel and then set it up between centres on the big heavy belt lathe I had at the time. Found the 'centre' of the banana like shown in the video kendog has posted the link to, then used the lathe tool turrent to press out the bend while the chuck was locked in position. Had to push slightly over centre to account for the barrel spring but got it absolutely perfect. That rifle shot perfectly with the straightened barrel and likely still going today somewhere.

This is a very interesting subject. I have used both Eagle's method on the big lathe and the hydronic,v block method mentioned by Snowman and Too Manny Tools.

Having been fitting moderators to rifles since the late seventies (.22's in the early days) I have cut varying lengths off,sometimes reducing to the clients request to 12" which is the minimum lawful length of a bbl here.
I always run it between centres to check before cutting it. The profile was generally running true or maybe just a couple of thou off.
However after cutting and recrowning I have seen them now with sometimes a .010,.020, .030 or worse T.I.R. between centres,which demonstrates how with some rifles (often new) have a bend in the rifleing which would never have shown up otherwise.So the next time you are wondering why you have need for so much scope adjustment lol....jc

Just a couple of comments, regarding "Straight" barrels, and making crooked ones, "straight".
One of the many jobs I had was being the Army Program Manager (PM) for Boresight Devices. Many Army systems have boresights such as tank cannons, Bradley cannons, and helicopter weapons. Also machine guns on tanks, etc. Small arms do not have them. (They have collimators). Anyway, we did a lot of testing to determine how the barrel affects the projectile flight. Long story short, it is the last three calibers (diameters) length of the bore that determines the path the projectile will take. The rest of the barrel's plane is of no importance. Tank barrels are all made to a specific profile, but they cost $100K each too.
So, while it is true that many barrels are not actually straight, it may or may not make any difference in the performance.
Another point; no custom barrel maker today (that I know of) straightens a barrel. They feel it introduces stresses into it that cannot be relieved, so, for example, Douglas never straightens them. They are gauged and if not straight, they are scrapped. Which very rarely happens with modern manufacturing techniques.
But when I need to straighten one, like the last FN-FAL I built that had a noticeably bent barrel, use a 20 ton press and v blocks. That works. They are easy to bend.

First, thanks everyone for the recommendations and advice. I thought though everything that was suggested.
Here is what I did:

I mounted the barrel between centers and using an indicator found the high spot, which was .153 out. I put a piece of tape around the barrel at that point and with a sharpie marked the high spot.

I moved the barrel over to my mill and put it between v-blocks with a dial indicator under the barrel. Using the quill I pushed downward on the barrel on the marked high spot. Lots of spring in the barrel, so I had to overshoot a lot, but after the first attempt I took half the .153 out, and then transferred the barrel back to the lathe to see progress.

First attempt got me within .031 BUT the high spot moved radially around the barrel by about 25-30 degrees. So I remarked that spot and moved back to the mill.

After about 11-12 iterations I got the barrel run out down to .004

I stopped at this point because pressure seemed to be moving the high spot around more than reducing runout. A couple of times I increased runout even though the indicator under the barrel was showing dead nuts. But when this happened it always moved the high spot radially at least 30 degrees. I can say for sure this was not a completely predictable process and both pressure required for a given deflection and the direction applied was not consistent with each result.

I suspect .004 is about as good as this thing ever was, but I now have a much better understanding of how little pressure it takes to permanently bend a barrel.

I'll wager there are a lot of bent barrels around, and what may be attributed to knocking a scope out of zero may in fact be a slight bend. I certainly have seen a lot of guns smack trees and such that would easily do what I has doing when "adjusting" for .10.

Have not shot the gun yet, but I don't know how it shot when it was new so any test will not provide a before and after comparison.

Thanks again.

Guess you got what you were after, but most would agree that the goal is to get the BORE straight..Don't want to get into debate about wall thickness.

Id opt to rebarrel in any case unless the firearm is collectable and no other choice existed..

A very interesting and informative thread.

I know that Shilen does not straighten any barrels. They have to meet strict specifications or they are scrapped. However back in 1993 I worked at a large gunsmithing concern in East Texas. At that time Shilen sold barrels that did not meet their specifications under the name Lone Star barrels. The shop owner was quite a salesman and he always bought the Lone Star barrels for rebarreling. He never mentioned to the customer that they were seconds, just quoting that they were Shilen. I didn't like it but I was just providing the labor not in sales.

I have straighted quite a few barrels over the years. Shotguns and .22 were easy as they are mild steel. The real stinkers were 98 Mauser military barrels. They were heat treated quite hard which made them really difficult. I suspect they were heat treated this way to prevent being easily bent under rugged military conditions.

Does anyone remember the gunsmithing instructor Bob Dunlap. Big guy with a dry humor. He gave the best instructions on this subject.

I heard a story a while back about an incident that happened at the Houston gun show. This guy has a booth with some top-end shotguns + he was advertising the hydraulic internal press that will take dings out of a shotgun barrel. Brownell's sells them. He had 2 models available, 12 G. + 20 G. Somehow or other he got crosswise with the guy in the next booth + this fellow picked one of the 1st guys dbls. + racked against a column then told him, STRAIGHTEN THIS!! Seems it was in a 16 G.