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Thread: Eureka......I Think I Found It!!

  1. #1
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    Eureka......I Think I Found It!!

    For those of you that followed my saga with that 7MM barrel that just would not shoot, I think I have the answer.
    In the other thread, I finally cut 2 inches off of it and it suddenly started shooting like a Benchrest Rifle.

    I didn't pay too much attention to the 2 inch piece I parted off, it wasn't that clean, as I was so disgusted with it the first go around I just took it off without cleaning it that well. Heck, I almost gave it away.

    Yesterday eavning, Dan Blair came by my shop, and we were talking about it, that piece was still laying on the headstock of the Lathe.

    He saw something. He then showed me. A distinct shadow about 3/4 inches long, just inside the muzzle. I cleaned the drop real good, and it would not disappear. You can easily feel it with a QTip.

    Look at the picture. You can plainly see it. It's a linear flaw, a bad spot.

    Keep in mind, I cut the usual 1inch from the muzzle end when I first chambered this Barrel.. It shot terrible. Apparently, cutting 2 inches off got rid of what ever that is.

    Not sure what this tells us. Except take a good look into the end of a new barrel if it shoots like cr-p.

    I might send this back to the manufacturer and see what they think.

    I'm happy. Mystery solved, the Rifle shoots great. For someone without my resources, I'm not sure there is an answer.



    http://benchrest.com/attachment.php?...1&d=1500400867
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    Last edited by jackie schmidt; 07-18-2017 at 02:29 PM.

  2. #2
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    That looks like a "squiggle" from the bore reamer when the barrel was made. When the bore reamer exits the barrel, it loses it's self pilot and can do funny things. Sometimes cutting deep enough that the rifling wont remove the defect when the grooves are cut. Some barrel makers ream the blanks from muzzle to breech, and others vice versa.

  3. #3
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    Quote Originally Posted by James Lederer View Post
    That looks like a "squiggle" from the bore reamer when the barrel was made. When the bore reamer exits the barrel, it loses it's self pilot and can do funny things. Sometimes cutting deep enough that the rifling wont remove the defect when the grooves are cut. Some barrel makers ream the blanks from muzzle to breech, and others vice versa.
    James, after work today, I took some JB compound and really got after that drop. I then cleaned it with Sweets, making sure there was absolutely nothing in that piece but Steel.

    The spot now has a distinct "frosted" look, different from the rest of the bore, about 5/8 inch long.

  4. #4
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    Quote Originally Posted by jackie schmidt View Post
    James, after work today, I took some JB compound and really got after that drop. I then cleaned it with Sweets, making sure there was absolutely nothing in that piece but Steel.

    The spot now has a distinct "frosted" look, different from the rest of the bore, about 5/8 inch long.
    Do you suppose you could have seen that if you had used a bore scope early on?

  5. #5
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    I think that someone owes you a barrel. That should not have made it through quality control. I wonder if it could have been felt using a snug lead slug or cast lap?

  6. #6
    Join Date
    Jan 2004
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    Manitoba Canada
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    Thus lies in Jackie's comment

    "For someone without my resources, I'm not sure there is an answer."

    The reason I took a long hard look at this sport and have decided to step away from trying to be serious/competitive in the game.

    My new Yamaha Cruiser is by far cheaper to run. Just put fuel in and turn the key and go. No practice needed or expensive barrels, bullets, or powder.

    Glad you were able to solve the mystery of the 7mm that just would not shoot.

    Calvin

  7. #7
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    Quote Originally Posted by jackie schmidt View Post
    For those of you that followed my saga with that 7MM barrel that just would not shoot, I think I have the answer.
    In the other thread, I finally cut 2 inches off of it and it suddenly started shooting like a Benchrest Rifle.

    I didn't pay too much attention to the 2 inch piece I parted off, it wasn't that clean, as I was so disgusted with it the first go around I just took it off without cleaning it that well. Heck, I almost gave it away.

    Yesterday eavning, Dan Blair came by my shop, and we were talking about it, that piece was still laying on the headstock of the Lathe.

    He saw something. He then showed me. A distinct shadow about 3/4 inches long, just inside the muzzle. I cleaned the drop real good, and it would not disappear. You can easily feel it with a QTip.

    Look at the picture. You can plainly see it. It's a linear flaw, a bad spot.

    Keep in mind, I cut the usual 1inch from the muzzle end when I first chambered this Barrel.. It shot terrible. Apparently, cutting 2 inches off got rid of what ever that is.

    Not sure what this tells us. Except take a good look into the end of a new barrel if it shoots like cr-p.

    I might send this back to the manufacturer and see what they think.

    I'm happy. Mystery solved, the Rifle shoots great. For someone without my resources, I'm not sure there is an answer.



    http://benchrest.com/attachment.php?...1&d=1500400867



    Which goes to prove a point I made a long time ago. A shooter who has a Lathe and can do his own machine work, has a distinct advantage in this Sport.

    Glenn

  8. #8
    Join Date
    Jun 2012
    Location
    West central NH
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    566
    To respond to Calvin's quote, I've had both motorcycles and competition rifles and I've had reasons to step away from both. I find that rifles in the safe keep better than bikes in the garage. Bikes not ridden caused me more worry than guns not shot. To each his own, however.

    I could have shot a 2-day match last weekend, but decided to stay home and putz. It was nice, and I needed the rest.

    I have an F-class rifle that I've invested a lot in and am not happy with it. I am thinking the barrel is just not stout enough for it's 30 inch length. I am planning to have 2 inches taken off. However, there's no hurry. It's doing just fine in the safe.

  9. #9
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    Quote Originally Posted by adamsgt View Post
    Do you suppose you could have seen that if you had used a bore scope early on?
    Yes.

  10. #10
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    Feb 2003
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    south beloit,il.
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    Badf Barrel

    Quote Originally Posted by adamsgt View Post
    Do you suppose you could have seen that if you had used a bore scope early on?
    Most barrel makers would have replaced barrel........ saving all the test ammo and hair loss.......
    bill

  11. #11
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    Feb 2003
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    Mt Pleasant Michigan
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    425
    They will probably tell you that you cleaned it improperly and it was fine when it was manufactured. But we can sell you another one.
    Joe Hynes

  12. #12
    Join Date
    Nov 2006
    Location
    Augusta, Maine & Palm Coast, Fl
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    6,147

    I recently

    Had the good fortune of having a barrel replaced by a maker because the barrel was out of their specs, they said so the "good Ones" will make things right. Not all of them do however.

    I have had barrels that have what I think are rough spots in them where fouling accumulates. No amount of polishing I have tried will take it out. I believe the rough spots to be inherent in the metal the barrels are made from. The barrels shoot well when they are not fouled but the accuracy does go away readily.

    Pete

  13. #13
    Join Date
    Feb 2005
    Posts
    280
    Quote Originally Posted by adamsgt View Post
    Do you suppose you could have seen that if you had used a bore scope early on?
    Unless there is some trick photography involved here, the presumed culprit is right at the end of the barrel and very visible to the naked eye. Now if it were down further in the barrel it would have been harder to find and probably would not have been the issue at all. Seems a very normal inspection of the barrel when cutting the crown or cleaning, would have made that spot a point of concern. In this case, what would someone's resources, have to do with something someone else noticed? Barrels are recrowned with satisfactory results every day.

    It would be very interesting to analyze these problem barrels with high speed cameras, which btw are becoming more accessible to the masses these days.

    The question remains for inquiring minds, is, was the blemish really the issue or was it the crown? Jus-sayin...

  14. #14
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    Apr 2008
    Location
    Cloudcroft, NM
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    Jackie

    I had a 30 caliber Kreiger barrel that I chambered up and it wouldn't shoot under .3" with any load I tried. Before I chambered it, I noticed some out-of-roundness in the grooves with my dial indicator. I called Kreiger, and they asked me to return the barrel. They replaced the barrel, and the new barrel shot fine.

    Still being bothered about loosing several hours of fitting and chambering time, and paying return shipping, I called them and asked for the old barrel back. I told them it should at least make a good hunting barrel. They agreed to send it back. About a year later I cut the chamber off and chucked the barrel up in the lathe. With the 2" removed, it indicated real nice. I decided to cut a new match chamber in it and try it on the bench gun again. It responded with an .082" group during a Raton match.

    Michael

  15. #15
    Join Date
    Sep 2008
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    131
    Quote Originally Posted by mturner View Post
    I had a 30 caliber Kreiger barrel that I chambered up and it wouldn't shoot under .3" with any load I tried. Before I chambered it, I noticed some out-of-roundness in the grooves with my dial indicator. I called Kreiger, and they asked me to return the barrel. They replaced the barrel, and the new barrel shot fine.

    Still being bothered about loosing several hours of fitting and chambering time, and paying return shipping, I called them and asked for the old barrel back. I told them it should at least make a good hunting barrel. They agreed to send it back. About a year later I cut the chamber off and chucked the barrel up in the lathe. With the 2" removed, it indicated real nice. I decided to cut a new match chamber in it and try it on the bench gun again. It responded with an .082" group during a Raton match.

    Michael
    Was the chamber end were the out of round was located?

    JR

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