Action "Stress" - Please Explain

Discussion in 'Main Message Board' started by Phil3, Dec 8, 2018.

  1. Bart B.

    Bart B.

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    The man who designed a lot of Roy Weatherby's sporter stocks in the '50's said stress free bedding is full contact with metal from receiver tang tip to fore end tip and don't tighten the stock screws. Then don't shoot it because the barreled action will still bend enough to stress the receiver and barrel.

    IOW, some stress is normal and harmless.
     
    Last edited: Dec 13, 2018
  2. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

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    You know what im gonna say- im from the original glue in school. If im going to shoot groups with it whether its a 22 or a 375 h&h its going to be glued in. If hunting or factory type accuracy is acceptable im going to pillar bed it and let the bedding run out in front of the action under the barrel and the recoil lug is going to touch only on the back and sides.
     
  3. Bart B.

    Bart B.

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    Won't that let normal fore end bending vary the pressure on the barrel?
     
  4. Phil3

    Phil3

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    I am the PO and read the linked article, and it is interesting. While not challenging that the improvement in accuracy was due to action screw torque and sequence, I am not convinced either. Consider the many things that could have changed during this test. The barrel was cooled when the test was repeated (good), but nothing is said about barrel cleaning or environmental conditions. I will presume shooter, environmental, setup, ammo, and EVERYTHING else remain absolutely identical and unchanged vs the previous test. If the barrel was not exactkly the same as the first test, then... There are so many variables that we cannot control, I find it difficult to attribute much of anything in accuracy to a specific change given the many potential other things that may change shot to shot. I would have liked to have done that exact test and not changed anything on screw torque to see what happens. Per my usual curiosity, assuming the screw torque sequence did affect the POI, I wish know WHY and HOW it did. I am not sure we will ever know that.

    Phil
     
  5. olddav

    olddav

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    I just performed a test of my own and I can’t tell you why it works but it does. The improvements on group size was pronounced. I went from 1 3/16” group at 15”# to 3/8” group at 30”# on the rear screw of a Savage 110.
    If anyone can offer an explanation as to why torque tuning works I too would love to hear it.
     
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  6. kountryboy2

    kountryboy2 Gold $$ Contributor

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    Maybe it's time to use a torgue plate when blueprinting actions.
     
  7. Bart B.

    Bart B.

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    I'd bet that changed vertical spread more than horizontal.

    Stock screw torque changes the compression fit of receiver to the stock changing how much it and the barrel vibrates. That changes the amount of barrel whip. And that changes the angles bullets depart at.

    One national champ high power shooter tested his Winchester 70 based rifle with different screw torque amounts, settled on 60 in-lbs for all 3. Some others testing Rem 700's found 40 to 45 in/lbs best. The difference may partially be the screw pitch, 28 tpi for Rem, 32 tpi for Win.
     
    Last edited: Dec 13, 2018
  8. Steve Jennings

    Steve Jennings

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    How about a barrel clamp on a 1 1/2" dia X 33" long straight barrel for F-O? It can be done and eliminates all related problems with your action bending.
     
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  9. olddav

    olddav

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    Mine changed from a nice triangle of 1 3/16" to a nice triangle of 3/8".
     
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  10. savagedasher

    savagedasher

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    It called a dam savage
    But it doesn’t the Same on all actions
     
  11. ebb

    ebb

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    When you take your rifle to the range all the other rifles are looking at yours and they are all thinking look at this piece of junk "I can out shoot this rifle with factory ammo!!!" Your rifle picks up on all this hostility, some rifles rise to the occasion others shoot bad cause of all the negative vibes. This is why you always shoot your best groups when alone or with only 1 or 2 friends. This is stress.
     
  12. savagedasher

    savagedasher

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    That why I shoot a SAVAGE
     
  13. Phil3

    Phil3

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    It would be interesting to know more about the rifle, the ammo, conditions, how measurements were conducted, shooting setup, how many groups, etc...all too much to list here. I would like to conduct such tests, but do not the have shooting venue.

    Phil
     
  14. Bart B.

    Bart B.

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    I've seen 2 Win 70 barreled actions so clamped in a 7" to 8" long square aluminum split block epoxied in wood fore ends.

    Sierra's early rail guns used such barrel clamps.

    They do good things.
     
  15. dmoran

    dmoran Silver $$ Contributor

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    Basically your describing the same thing that many use in 1000yd Benchrest Heavy-Guns today (pictured below)(a 65lb HV-Gun) are. But at the same time, you repeatedly claim your Win70 sling guns of yesterday are just as accurate as benchrest rifles of today.

    BK-HV.png
     
    Last edited: Dec 13, 2018
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  16. Bart B.

    Bart B.

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    If you ever learn that when any shooting system's 4 major elements are repeatable, all bullets will go in the same hole, maybe you'll understand.

    I don't think you're there, yet. Keep trying, best wishes. Note the record 1K yard aggregate's composites have all shots in 6, maybe 7, inches. The tiny 5-shot records are dwarfed by them.

    Remember, nobody will use that 65# heavy bench gun to win a sling gun prone match even if its biggest test groups benched are 5/8th inch at 1000.
     
    Last edited: Dec 13, 2018
  17. olddav

    olddav

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    The test was a basic one. Three shots per torque value. All shots were taken with front and rear bags. Each group was shot at its own target and labeled with the corresponding numerical torque value. Started at 15"# and increased 5"# until reaching 35"#.
    The ammo was my own reloads using Winchester brass, WLR primers, IMR 4895 (51.9 grains) and Barnes 210 TTSX bullets. Bullet jump is .060 to the lands. Recent experience suggested this load would not group that well in the temperature I was shooting (50°). I shot two groups then let the barrel rest, (it never got warm to the touch). Targets were measured on the bench (center to center) with a simple measuring device (tape measure).
    The rifle is a basic Savage 110, factory wood stock (pillar & glass bedded), Shilen (prefit) barrel chambered in 338-06, and a tuned 3 screw trigger.
     
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  18. BoydAllen

    BoydAllen

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    A friend who had very good military connections once told me that for their bolt action competition/sniper rifles that they are tested at torque settings in five pound increments, starting at 45 pounds, loosening the action screws and resetting them for each successive test, to determine what works the best for that rifle. One thing that probably needs to be said is that some who are in this discussion need to consider who they are replying to, and consider that verified match reports carry more weight than other accounts that are not similarly verifiable. I not speaking of myself here. I just try to relate personal experiences to the extent that they may contribute to the discussion. There is a lot more going on with non glued bedding than action stiffness, a lot more.
     
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  19. varget204

    varget204

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    You want to contact stockmaker / firearm Co.They can give you Recommended INCH POUNDS of Torque,You Always want to adjust Front Screw Last. Some guns it's the same on ea,some 3-5" pound more on Front Screw. Some more, ETC.The only way to tell,shoot groups and see what works on your barreled action.You will see a difference. when you start to over torque,groups will open up. I have a BC stock needs 50" on both,1 w 40",another w 40" front 35" rear.They are all different.I've talked to guys using up to 60" pounds or more on some Remingtons,Ruger rifles.Always check to see if the Bolt is Binding.Should be as free as it is not torqued.
     
  20. Bart B.

    Bart B.

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    How much stress does a free floating, 30" long, 9 pound barrel put on the receiver?

    Then add the barrel whip caused by big cartridges shooting heavy bullets really fast.
     

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