How Many Tune Rifles with Action Screw Torque

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by phorwath, Mar 29, 2010.

  1. phorwath

    phorwath Well-Known Member

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    Some members in a separate thread described tuning their bolt action rifles for optimum accuracy by adjusting the torque on their actions screws. I've never tried this before. Some posted some large reductions in group sizes by lightening or tightening the torque on the action screws.

    How many have tried this enough to confirm that groups sizes will shrink or enlarge with different action/bedding screw torque on bolt action rifles? Care to share your approach and thoughts?
     
    Last edited: Mar 29, 2010
  2. BountyHunter

    BountyHunter Writers Guild

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    Not me, torque em down to 65 lbs and tune with the load.

    Now some have found that certain guns just wil not shoot there, but that is the exception rather than the practice.

    BH
     

  3. Broz

    Broz Well-Known Member

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    Interesting topic. I hope to learn something here. I always figured if it was bedded properly it should not matter if it is 50 or 65 in lbs.

    Jeff gun)
     
  4. BountyHunter

    BountyHunter Writers Guild

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    Probably the number one problem with ill shooting guns now. You would be surprised at the guns you see with that issue.

    Set up the gun in a vise with a dial inidicator on the barrel and release the stock screws and see if the indicator moves.

    BH
     
  5. nddodd

    nddodd Well-Known Member

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    I've done it with three different rifles two were Remington senderos one bedded and one not. I've also done it with a savage target action 338 edge.

    My two senderos started at 35 in lbs and my stw wound up shooting best at 65 in lbs and my 300 ultra shot better at 50 in lbs. Went in 5 lb increments.

    My savage target action started at all three at 30 in lbs and left the rear screw there and worked the center and the lug screws up together in 5 lb increments all the way to 50 but it shot best at 45 in lbs.

    All my shooting was done at 250yds.


    Just my experience,
    Nathan
     
  6. jwp475

    jwp475 Well-Known Member

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    +1...........
     
  7. LouBoyd

    LouBoyd Well-Known Member

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    if the action changes position with respect to the stock between shots a rifle not going to be accurate. There should be a comfortable region between where the stock is so loose it changes position with firing and so tight it warps or crushes either the action or the stock. What that range may be depends on the recoil , the stock material, and the stock and action design. I test my rifles by adjusting the action screws both a little high and low separately to be sure there's a zone where the adjustment makes little difference and it shoots well. I prefer to run the screws about 10 in/lbs over where the accuracy falls off from being loose but not to exceed 60 in-lb. (for a Rem 700 in a fiberglass or pillar bedded stock.). The screw size, action type and stock material all matter in determining what torque to use.

    I never "tune" a rifle to purposely shift the barrel harmonics using the action screws. It certainly can do that, but it means the effective position that the action is attached to the stock is shifting with screw tension which it should not. It can of course do that with a poor bedding job or if the action is "bent" over the magazine assembly. I only use screw torque as a diagnostic tool. It's the bedding or inletting which should be changed if it's not right.

    There's not much point in doing load development until it's been determined the barrel and stock aren't shifting. That's true for the action to scope interface too.
     
    Last edited: Mar 29, 2010
  8. elkaholic

    elkaholic Well-Known Member

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    Very interesting topic! I have seen rifles that were finicky about torque but I always felt it was a bedding problem. I believe if an action is properly bedded, there is a much larger window of acceptable torque and only enough torque is needed to keep things from moving with additional torque not affecting anything one way or the other. I will be very interested,however; in what others have found.......Rich
     
  9. trueblue

    trueblue Well-Known Member

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    +1 on torque to 65# and tune with the load.
     
  10. 7mmSendaro

    7mmSendaro Well-Known Member

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    I agree on the 65 inch pounds and tune the load. That being said, I don't do anything until the rifle is bedded complete with pillars.
     
  11. Broz

    Broz Well-Known Member

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    This is what I have always done too, and I think the key part is "bedded complete with pillars"

    Jeff
     
  12. ovastafford

    ovastafford Well-Known Member

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    I have always just tightened them enough that they wouldnt come loose. I personally think that if you are having to adjust tension for accuracy then you have bedding issues.
     
  13. The Duke007

    The Duke007 Well-Known Member

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    I have a problem with accuracy. I found that the action screws were a little loose. I tightened them to 60 ibs. Does anyone know if this would fix the problem? I would go to the range but I dont have time right now but if someone knows it would help.
     
    Last edited: Nov 15, 2010
  14. Trickymissfit

    Trickymissfit Well-Known Member

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    I've been experimenting with action screw torque for about four or five years now. I started out with a regular 3/8th's torque wrench (one with a dial), and now use a precesion 1/4" drive wrench made like a screwdriver. At this time I'me using two different settings for the screws. The front ones are set at 40 in. lb. and the rear is set at 35 in. lb. on a couple Savages. My Remington is still in the learning curve, but the 35 in. lb. values seem to be a good starting point. I do coat my threads with Never Sieze, and bring the bolts down in ten in. lb. increments. Funny thing was that when I checked the break away torque after tightening the bolts down I was getting slightly less than 50 in. lb. I have not done any experimenting with my Weatherby rifles, so I can't say alot about them.

    If your shopping for a wrench, be sure to get one that will put the window your torque values are in somewhere in the middle of it's range. The bottom 20% and the top 20% are not all that accurate in most wrenches. They also make them in two different grades. A 5% and a 10% accuracey wrench. Look for the 5% as they are built better and will keep their calibration much longer. Stay away from the ones that donot use a dial or a wand. The break over ones are known to over torque screws easilly. They make digital read out ones, but they are way too expensive, and not really needed. Also use a good allen socket! A worn out cheap one will give you a false reading.
    gary