Author Topic: Barrel bending question  (Read 12169 times)

Offline Nate McKenzie

  • Hero Member
  • *****
  • Posts: 1019
  • Luzerne Co. PA
    • Nathan McKenzie Gunmaker
Barrel bending question
« on: July 12, 2008, 09:53:32 PM »
Argh! It finally happened after many years. I just completed a rifle with an "A" wt. swamped 38 in. barrel. Went to sight it in today and I'm out of adjustment both front and rear. Built needs to go about 2 more inches right. Guess I'll have to bend the barrel. My question is this. When I clamp both ends of the barrel and clamp the middle to bend it, Do I move the middle toward or away from where I want the bullet to go. Any guidance would be greatly appreciated. Any better ideas? Thanks for any comments or suggestions.

Offline Frank

  • Hero Member
  • *****
  • Posts: 968
Re: Barrel bending question
« Reply #1 on: July 12, 2008, 10:45:09 PM »
Send it back and get another one.

Offline Ky-Flinter

  • Global Moderator
  • Hero Member
  • *
  • Posts: 7472
  • Born in Kentucke, just 250 years late
Re: Barrel bending question
« Reply #2 on: July 12, 2008, 10:46:10 PM »
Hi Nate,

I recently had to bend one "straight".  First, I would make darn sure yours is actually bent AND which way.  There are other things that could cause it to shoot left, like problems with the muzzle crown or cone, pressure from the wood of the stock or the barrel pins or who knows what else.

Take the barrel out of the stock.  Get a long straight-edge, metal yard stick, etc.  Lay it along side the right flat and measure the gap at the widest point (dial calipers work well here)  This will likely be in the waist of the barrel, since it's the thinnest and most likely area to get bent.  Write down the measurement.  Measure the opposite (left) flat at the same spot.  Are the measurements the same?  If so, that plane is straight. Repeat for all 4 sets of flats.  

The barrel I had to bend straight was a 38" B weight in 50 cal (thin walls!).  With the sights pushed over to the max, it was shooting 8 inches left at 25 yards.  The gaps on my 2 flats were .180" on the left flat and .100" on the right flat, if I remember correctly.  But it was definitely bent.  I called the barrel maker and he suggested straightening, but if I didn't want to or I couldn't get it straight, he offered to replace it.  You can't beat that.  I would call your barrel maker to discuss your situation.

If you do decide to straighten, I would not clamp the ends of the barrel, as they will want to move.  I used a piece of 2" square steel tubing for my base fixture and set a block of oak under each end of the barrel.  I used a big C clamp to bend the barrel.  You want to push on the flat with the least gap.  You won't believe how much you have to bend the barrel, because it will spring back.  It's trial and error.  Bend a little, measure both flats...  repeat until the gaps are as even as you can get them.

Or you could just put in the crotch of a tree and give her a yank.

Good luck.

-Ron
« Last Edit: July 12, 2008, 10:54:28 PM by KyFlinter »
Ron Winfield

Life is too short to hunt with an ugly gun. -Nate McKenzie

tg

  • Guest
Re: Barrel bending question
« Reply #3 on: July 13, 2008, 12:10:58 AM »
I would suggest trying to get a new barrel, bending smoothbore barrels is a regular thing, if you cannot adjust the sights to bring a rifle in I would ask for a new barrel it has runnout or was bent when you got it.

Birddog6

  • Guest
Re: Barrel bending question
« Reply #4 on: July 13, 2008, 12:56:15 AM »
May not be bent, may be bored in a arc from a dull bit or too much pressure or both. I had this happen on a .36 cal "A" barrel in a rifle I built a few years back. It shot 1' low & 9" left first time I shot it. Sent the barrel back & they replaced the barrel.  Now I shoot them ALL  as soon as I get the barrel pinned in & a lock & trigger in, as I want to know ASAP if the bore is correct, not after I have the rifle built.

Eliminate the obvious first, stock pressure, etc.  If that is not it, send it back to the barrel maker & let them see what is wrong & let them bend it if it needs bent or replaced.

Offline Acer Saccharum

  • Administrator
  • Hero Member
  • *
  • Posts: 19311
    • Thomas  A Curran
Re: Barrel bending question
« Reply #5 on: July 13, 2008, 01:24:57 AM »
If you already have dovetailed lugs under the bbl, that is where the bend will want to take place.
Tom Curran's web site : http://monstermachineshop.net
Ramrod scrapers are all sold out.

Ephraim

  • Guest
Re: Barrel bending question
« Reply #6 on: July 13, 2008, 02:06:08 AM »
Who made the barrel they should make it right.
Ephraim

Offline T*O*F

  • Hero Member
  • *****
  • Posts: 5118
Re: Barrel bending question
« Reply #7 on: July 13, 2008, 02:21:54 AM »
You don't just jump in and start bending a barrel and you don't determine if it's bent from outside measurements.

Take the barrel out of the stock and de-breech it.  Run a stout thread or fine wire down the bore and pull it taut at both ends.  It should touch the lands all the way down the bore.  If it doesn't, check several places around the circumference until you find the greatest gap.  That's where you'll concentrate your bending.  Then bend to eliminate the gap.  Continue until there is no gap anywhere around the circumference of the bore.  It may take several bends to achieve this.

If there is no gap, then your problem lies elsewhere.
Dave Kanger

If religion is opium for the masses, the internet is a crack, pixel-huffing orgy that deafens the brain, numbs the senses and scrambles our peer list to include every anonymous loser, twisted deviant, and freak as well as people we normally wouldn't give the time of day.
-S.M. Tomlinson

George F.

  • Guest
Re: Barrel bending question
« Reply #8 on: July 13, 2008, 02:56:31 AM »
This is the first I've heard of needing to bend a new barrel , especially from todays barrel makers.  Shooting that far off at such short distances, it's amazing. Is this more common than is reported?

Offline Dphariss

  • Hero Member
  • *****
  • Posts: 9919
  • Kill a Commie for your Mommy
Re: Barrel bending question
« Reply #9 on: July 13, 2008, 03:27:37 AM »
This is the first I've heard of needing to bend a new barrel , especially from todays barrel makers.  Shooting that far off at such short distances, it's amazing. Is this more common than is reported?

My experience with ML barrels indicates that they need to be  carefully looked at and slugged before doing any work on them.
Smooth or rifled.
Dan
He who dares not offend cannot be honest. Thomas Paine

don getz

  • Guest
Re: Barrel bending question
« Reply #10 on: July 13, 2008, 05:05:57 AM »
Nate.....I see that you live up in Benton...that's about a 1 hour drive from Beavertown.  If you bring it down, I'll check it
and straighten it if it's bent.   Call me if you want to come down, just to make sure I'll be there....717-463-4041, or
E-mail at "dggetz@nmax.net".  This is my home phone number and email address.  An A weight barrel is a thin barrel and can be bent in many ways, so don't jump on the barrel maker right away.  It could happen in inletting, or some other way,
the best thing to do is check it first, then proceed.  I'm almost certain is not one of our barrels but that doesn't matter,
I'll be happy to check it for you anyway.  I don't mean to infer that it can't happen to a Getz barrel, I am just saying I
don't think it is one of ours............Don

Offline C Wallingford

  • Hero Member
  • *****
  • Posts: 863
  • Northern Kentucky
    • CW Knives
Re: Barrel bending question
« Reply #11 on: July 13, 2008, 03:28:22 PM »
Don is correct. A barrel can get bent in the building process. I have had it happen on several occasions when using thin wall barrels. So far I have been successful in getting them straightened.

Offline Acer Saccharum

  • Administrator
  • Hero Member
  • *
  • Posts: 19311
    • Thomas  A Curran
Re: Barrel bending question
« Reply #12 on: July 13, 2008, 06:12:56 PM »
Also if it's a thin wall barrel, any stress from the wood can cause the barrel to point one way or another.  When you take the barrel out, does the stock have a serious left or right set? if so, you may have to straighten that.

Make sure that the lugs have slots big enough for the wood to shrink/swell fore and aft.

« Last Edit: July 13, 2008, 06:13:23 PM by Acer Saccharum »
Tom Curran's web site : http://monstermachineshop.net
Ramrod scrapers are all sold out.

Offline Ky-Flinter

  • Global Moderator
  • Hero Member
  • *
  • Posts: 7472
  • Born in Kentucke, just 250 years late
Re: Barrel bending question
« Reply #13 on: July 13, 2008, 06:57:05 PM »
.....and you don't determine if it's bent from outside measurements.....

Dave,

Your method will certainly work but it's not the only way.  On the barrel I had, I consulted the maker before I took any action.  He agreed with my measuring process, since he machines the bore first, then cuts the outside flats, meaning the wall thickness should be fairly uniform.  I made the assumption that Nate's barrel had also been made this way.  All the more reason to consult the maker, as I suggested, before taking any action.

As for how they get bent, my barrel maker said most times it's UPS.

-Ron
« Last Edit: July 13, 2008, 06:59:00 PM by KyFlinter »
Ron Winfield

Life is too short to hunt with an ugly gun. -Nate McKenzie

Offline T*O*F

  • Hero Member
  • *****
  • Posts: 5118
Re: Barrel bending question
« Reply #14 on: July 13, 2008, 08:04:42 PM »
Quote
Your method will certainly work but it's not the only way.
Ron,
My method is one which has been used as long as barrels needed to be straightened.

Your method and straightening procedure seem to be flat-oriented.  What if the bend is not located on one of the flats, but on one of the oblique edges, or worse yet slightly offset to one.  This negates plunking the barrel on one of the flats in the straightening fixture.  One needs to find exactly where the apex of the bend is in order to apply pressure to reverse it. Ce n'est pas?
Dave Kanger

If religion is opium for the masses, the internet is a crack, pixel-huffing orgy that deafens the brain, numbs the senses and scrambles our peer list to include every anonymous loser, twisted deviant, and freak as well as people we normally wouldn't give the time of day.
-S.M. Tomlinson

Offline Nate McKenzie

  • Hero Member
  • *****
  • Posts: 1019
  • Luzerne Co. PA
    • Nathan McKenzie Gunmaker
Re: Barrel bending question
« Reply #15 on: July 14, 2008, 04:50:38 PM »
Thanks a lot to all who responded. What a great bunch of people.

Offline Roger Fisher

  • Hero Member
  • *****
  • Posts: 6805
Re: Barrel bending question
« Reply #16 on: July 14, 2008, 05:20:16 PM »
I have never had to bend straight a rifle barrel just lucky I guess.  Did have to bend straight a smoothy that shot low right at 30 yds abt 6 inches.  Used heavy plank with blocks - shims and clamps.  Had to bend/straight farther than I wanted to a couple or three times.  When I laid her back in the stock I noticed that she was moved.   She shot on then.  Again in my case good luck prevailed since I didn't do a darn thing machinist style.   ;D

USMC Sgt.

  • Guest
Re: Barrel bending question
« Reply #17 on: July 22, 2008, 04:39:59 AM »
Nate,  You should get a gunsmith or a barrel maker to show you how to look Thur the bore and pick out where the bend or crook is.To just clamp it and spring the barrel in the direction it needs to shoot may just cause another bend or crook ,if you don't know where the original bend is. The only proper way to do this is to look Thur the bore. I am sure you could learn it if you could get some one to show you how. If you get around my area I would be glad to show you how. Charles R. Heistand

Offline Jim Filipski

  • Hero Member
  • *****
  • Posts: 642
    • Jim W. Filipski  Flintlocks
Re: Barrel bending question
« Reply #18 on: July 22, 2008, 04:52:07 PM »
Funny story about barrel bending:
About 1992 I built a 20 ga French Fowler for a guy who was a "shooter" Now before I gave it to him I thought it shot pretty well with round ball especially for a smooth bore.
When he got it he was determined to make it shoot "where he looked"! I can't even tell you the horror in my mind the first time he called and said he had had the barrel out of the stock about six times to bend it! When he was satisfied he took the gun to a big smoothbore shoot and took 1st place for round ball 50 yards.
Oh yeh! he also shoots shot with it better then most folks shoot modern guns. So I guess it can be done well. He used wood blocks & a table most times however he did mention trying what an old timer said about putting the barrel in a tree crotch...oohh. Crazy thing is he never checked the bore just keep tweaking it until it did what he wanted.....scary way to do it. Well anyway that gun is his prize possession. took a lot of shooting matches and made a lot of food. 
Some how however I think it really is what Jerry H has said a bunch of times "It's not the pick that make the guitar sound so good"
Jim
" Associate with men of good quality,  if you esteem your own reputation:
for it is better to be alone than in bad company. "      -   George Washington

"A brush of the hand
of Providence is behind what is done with good heart."

Offline Roger Fisher

  • Hero Member
  • *****
  • Posts: 6805
Re: Barrel bending question
« Reply #19 on: July 22, 2008, 05:17:56 PM »
Funny story about barrel bending:
About 1992 I built a 20 ga French Fowler for a guy who was a "shooter" Now before I gave it to him I thought it shot pretty well with round ball especially for a smooth bore.
When he got it he was determined to make it shoot "where he looked"! I can't even tell you the horror in my mind the first time he called and said he had had the barrel out of the stock about six times to bend it! When he was satisfied he took the gun to a big smoothbore shoot and took 1st place for round ball 50 yards.
Oh yeh! he also shoots shot with it better then most folks shoot modern guns. So I guess it can be done well. He used wood blocks & a table most times however he did mention trying what an old timer said about putting the barrel in a tree crotch...oohh. Crazy thing is he never checked the bore just keep tweaking it until it did what he wanted.....scary way to do it. Well anyway that gun is his prize possession. took a lot of shooting matches and made a lot of food. 
Some how however I think it really is what Jerry H has said a bunch of times "It's not the pick that make the guitar sound so good"
Jim
Here's another!!  Goes back around 20 yrs or some such!  At Whispering Pines Rondy in N,. Penna. a shooter was shooting holes in one of those Dixie Gun Works newspaper quality round bull targets and the holes were way down at 6 O'clock. I asked him if those marks were friendly flies.  (The Gypsy Moth killer flies!)  He finally took the bands off and pulled the barrel out of this Charleville.  He eye balled the barrel walked over to a 'bunch' of maple trees slid the barrel therein, gave it a yuks or so.  Stuck it back in the stock and was in the 'black' no problem.  This young kid -later became one of our better NMLRA presidents!!   ;D

Daryl

  • Guest
Re: Barrel bending question
« Reply #20 on: July 23, 2008, 02:49:27 AM »
Nate - before you go to bending it, or traveling to get it bent, try some different loads.  The barrel torques upon firing, and depending on which direction the muzzle is pointed, determines if the balls fall in line or not.
: Both my .40 and .45 barrels exihit some windage shift or changes between light 55gr. loads and the loads that are the mose accurate.  By this I mean, that I have to decide if I want a reasonably accurate load, or the best load. The most accurate load with 3F strikes 1" left of the light light load and the best load with 2F shoots 1" right of the light load.  Both heavy loads strike 1 and 1 1/2" low of the light load. Should I bend- no way, the sights can both be drifted slightly in their dovetails to make up that difference. A file, or re-solder of the bead makes up for the elevation error.

Daryl

  • Guest
Re: Barrel bending question
« Reply #21 on: July 23, 2008, 02:53:45 AM »
As to bending smoothbores, Taylor used a handy Aspen tree ??? with about a 14" trunk to smack his Bess barrel against :o. It now shoots plum centre  ;D.  The adjustment had to be both elevation and windage. Oh well.