?To nut or not to nut?

Discussion in 'Gunsmithing' started by bigngreen, Sep 3, 2010.

  1. bigngreen

    bigngreen Well-Known Member

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    I'm getting ready to build two 338's on Savage long actions, I was thinking that with the longer 30in+ heavy barrels that shouldering the barrel conventionally and not using a nut would support the barrel better but I know some of you guys are rocking monster tubes with the nut, I need some pro and cons here.
    Barrel swapping is not a prime concern, consistency and accuracy are!!!
     

  2. 300R

    300R Well-Known Member

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    Hey Mate these builds of your's are leaving you little time for sleep i can see:D!Are you still considering the 338 norma.
     

  3. Fitch

    Fitch Well-Known Member

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    If it were me, I'd true the action, or at least machine the receiver front face square to the bolt bore, get a precision ground recoil lug, and use a shouldered barrel with out the nut. The reason is shouldering the barrel to contact the recoil lug directly eliminates any misalignment that might be built into the nut.

    The pro is elimination of a potential source of misalignment and thus possibly better accuracy. The con is that the barrel will only fit that particular action. You pick your pony and take your ride.

    Fitch
     
  4. bigngreen

    bigngreen Well-Known Member

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    Very little sleep, I gotta get it all straight in my mind and on paper then I can settle down and start ordering parts!

    There is something about the 338 Norma Mag that just grabs me so I had better build one and get it over with :D
     
  5. bigngreen

    bigngreen Well-Known Member

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    I've trued a couple nuts and it improved accuracy so I think the nut can be a real source of problems. I'm not worried about switching barrels, these will be long life chamberings on dedicated LRH rifles so staying very stable and consistent will be the primary goal, that's why I'm leaning nut less.
    Thanks for the feed back Fitch.
     
  6. 300R

    300R Well-Known Member

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    I think you answered your own question mate, go with your gut.

    Im with you on the 338 norma i really wanna build one too ,i love the fact it is designed around the 300 smk,works in a short barrel,fits in a standard magazine and has proven inherently accurate by design but if i were you i would stay with a 26' barrel maybe even shorter, most of the testing was done in shorter barrels.Do you think the shorter heavy barrels has something to do with better accuracy?
     
  7. BobbyL

    BobbyL Well-Known Member

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    If your not going to be switching barrels leaving out the nut is the only way to go.
     
  8. J E Custom

    J E Custom Well-Known Member

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    There is a post on 6 BR that addresses this question and it appears that it is up to the
    Smith and the owner.

    I will always use the shoulder instead of the nut unless the owner wants to use the nut.

    Like Fitch said . It is one more source of problems and I have not found them to be square.

    J E CUSTOM
     
    Last edited: Sep 3, 2010
  9. Trickymissfit

    Trickymissfit Well-Known Member

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    engineering wise the barrel nut is the only way to go! Here's why: when you seat the barrel on the shoulder the barrel threads are actually in suspension with about 25% thread contact at best (if you can screw the barrel into the reciever you have clearence). Nobody grinds the threads, and even fewer would even know how to grind an internal thread for a near perfect fit. But with the nut you actually stretch the barrel thread and thus greatly increase the thread form contact area. What this does is that it makes the threaded portion of the barrel stay strait instead of whipping when the four vectors of force hit the threaded area of the barrel during ignition (there's actually six when you add the bolt face into the equation). There's another way to avoid this, but I won't go there as it can send you to the hospital real fast if done even slightly wrong on a big bore gun.
    gary
     
  10. winmag

    winmag Well-Known Member

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    Man, you pose a question like that and I figured youd get some hilarious responses. So far everyones being classy.
    I however lost all my sophistocation and class when I read the title to your post.... :DHAHAHAHAHAHAAHAHA:D:D
    I have no idea how to answer in a serious manner except as mentioned before ''go with your gut''. ''Nuttless'' seems to be the general consensus, make a ''Unik'' out of it hehehehehehe.................sorry I couldnt help it:D
     
  11. J E Custom

    J E Custom Well-Known Member

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    I will have to contradict the 25% thread contact because If a smith does his job right the
    thread contact is almost 100% .

    I have cut threads that could not be made up by hand and then simply chased the threads
    without changing the compound settings and it would make up although tight and with no
    slack or movement.

    If the tool has the proper angle and pitch it can be fitted to any reciever nearly perfect.

    The reason you stated , is the very reason dont like the barrel nut system. It is a cost
    saving method and to assemble a rifle with this system all you need is an trained operator/assembler and not a gun smith.

    A rifle that has a shouldered barrel has to be set up by a smith and head spaced before
    assembly.

    There is nothing realy wrong with the system its is just not precise enough to suit me
    and I'm sure others.

    So no mater what system is used 25% thread engagement is not enough.

    If I do a savage with the nut I will always get 95%+ thread fit between the barrel and
    the receiver before the nut is installed I will redo it.

    This is not an attack just my opinion.

    J E CUSTOM
     
  12. geargrinder

    geargrinder Well-Known Member

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    I've built two myself. I kept the nut on both of them. The heavy one has a 32" #7 contour.

    If you went nutless, it would be as ugly as a Remington. Sorry, couldn't resist.:D
     
  13. bigngreen

    bigngreen Well-Known Member

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    :D:D:D I'm kinda having remorse about even thinking about loosing the nut, if someone mistakes it for a Remington I might snap or cry, they should be able to tell by how it shoots that it is a Savage anyway :D
    Kinda like when your kids are little and someone mistakes your little girl for a boy and you have to kindly, but firmly straighten them out before your wife hears them and opens a can on them .

    I really like your gun geargrinder but I find myself struggling with having a super nice taper then step down to the nut and I just can't get it out of my mind having all that weight hanging out there.
     
  14. Trickymissfit

    Trickymissfit Well-Known Member

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    first of all when deal with threads that are larger than an inch in diameter the best you can ever hope for is roughly a 60% thread. Some folks do say they can get 65%, but I've never seen anything close to that. (read the Machinest Handbook, or better yet order a copy of thread form statistics from the Bereau of Standards from the Government. This 60% is a Class 1 ground thread. You cannot get the proper helix angle turning a thread in a lathe. A thread that's around 1/2" is best at around 70% to 75%, but the actual contact of the thread form (male to female) will be less. It just a fact of life.

    Secondly, should you manage to get that 95% thread contact; all I can say is good luck putting it together. And if by chance you do get it together; then good luck ever getting it apart

    do this: Cut a 1.05 thread to match the Savage nut. Now take a magic marker and coat the threads on the male part. Screw it together, and then take it off by screw the nut all the way accross the turned thread. Look at it under a strong light and a magnifying glass. Better yet, if you have access to a shadowgraph. Then cut a section of the nut, and clamp it to the thread form. Results make you wonder how the threads even went together.

    not being critical, but I made a living doing this for almost 40 years, and it's just the nature of the beast.
    gary