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Should an AR's castle nut be staked?

Discussion in 'Rifle Country' started by Hokkmike, Jun 6, 2019.

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Should an AR's castle nut be staked?

  1. #1. YES

    31 vote(s)
    41.9%
  2. #2. NO

    4 vote(s)
    5.4%
  3. #3. Both are acceptable

    33 vote(s)
    44.6%
  4. #4. Other - explained in response

    6 vote(s)
    8.1%
  1. amprecon

    amprecon Member

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    DerMerchant likes this.
  2. Hookeye

    Hookeye Member

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    Well the stake area is not on the castle side of the nut so it is for wrench use only.
     
  3. Hookeye

    Hookeye Member

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    My guess is the castle for a simple but specific wrench that allows easy component install and removal that minimizes risk to important threaded region
     
  4. Varminterror

    Varminterror Member

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    Using notched buffer tubes makes a bit of a difference in how much influence a castle nut can have.

    8320DA12-3D15-4AA5-97EB-D4FEB13887E9.jpeg A3C2ADB2-DD60-491B-A96A-DD7CE07A0DB8.jpeg
     
  5. Doc7

    Doc7 Member

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    Yes, for me because why not? It takes as much time as it takes to get out your steel punch and swing a hammer twice.
     
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  6. Mn Fats

    Mn Fats Member

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    That's interesting. Can't you turn it so it is? The slots on a castle style nut are literally there for a pin or stake. Not for a tool. It seems in an AR they used it for a specialty wrench while eliminating the squared edges of a regular nut.

    If it wasn't staked or didn't have some sort of lock washer, a little blue loctite is what I would do.
     
  7. coloradokevin

    coloradokevin Member

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    You can do whatever you please. The textbook way of doing it involves staking the castle nut. With that said, I haven't staked any of the ones I've built myself, and I've never had one come loose on me, either. I always figured I could easily retighten it if it came loose, and I'd wait for that to occur before I bothered staking... it never happened, so I never staked it.
     
  8. coloradokevin

    coloradokevin Member

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    Well, I know of a few non-firearm applications where castle nuts are used and staking specifically isn't specified. I don't think the presence of a castle nut alone indicates that staking is necessary. Again, I suppose it's really up to the user, their level of comfort with either way, and their expected use for the rifle.
     
  9. Pat Riot

    Pat Riot Member

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  10. Skylerbone

    Skylerbone Member

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    The AR castle nut was designed to be staked, the only reason it has notches cut on the side opposite the “turret” side. The very purpose of using a castle nut in any application is for its ability to be staked or pinned.

    Ultimately it may not be necessary in the case of the AR but the design spec makes the intent clear.
     
  11. MistWolf

    MistWolf Member

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    If you use the SBA3 arm brace, there's no need to change the RE. Just swap the brace for your favorite buttstock.

    Last time I checked, Knight's Armament does not stake their castle nuts. They also have very specific and tightly controlled assembly processes. If the castle-nut is to not be staked, the threads must be properly cleaned and the nut torqued correctly. The fit between the lower receiver and receiver extension and the receiver extension and castle-nut must all be correct. The castle-nut must be torqued correctly. Not all receiver extension parts fit together well.

    If you are uncertain as to prep, fit or process, stake your castle-nut. Stake it properly. Over staking will result in pushing the endplate into the threads and damaging them. Remember- The primary function of staking is to keep the nut from loosening from vibrations. It's secondary function is to keep the nut from spinning if it's not torqued correctly. It is not a substitute for torque or to make up for improper torque.
     
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  12. Hookeye

    Hookeye Member

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    BTW, there are non castle type nuts for buffer tubes that have provision for staking.
     
  13. Skylerbone

    Skylerbone Member

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    Same brace I used on my first pistol lower and I did indeed stake the extension. I specifically purchased the SBA-3 for its use of a standard carbine extension, great product.
     
  14. DerMerchant

    DerMerchant Member

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  15. Doc7

    Doc7 Member

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    I stake my extensions and it’s still super easy to put a wrench on and remove the nut. You don’t go crazy, just a few thousandths to prevent backing out without a wrench. Staking is literally all pros and no cons.
     
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  16. DerMerchant

    DerMerchant Member

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  17. cougar1717

    cougar1717 Member

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    Again, this is one of those questions where one has to ask why the military does something and if it makes sense for civilian use. Just because it's mil-spec doesn't mean that it unilaterally the "best" ever.

    The military has the option of full auto fire. FA fire is much more rigorous on the recoil buffer assembly. It's much more important in FA that the castle nut does not move and the buffer tube does not loosen if the rifle is to function correctly.
    In contrast, **most** civilians will only fire semi auto, ever. Sure, bump stocks and triggers that intentionally cause doubling exist, so extended "fast semi auto fire" means a greater chance for the castle nut loosening. If that is how you roll, just stake it.

    Soldiers have no choice in their buffer tube extension. Civilians can reconfigure their buffer tubes to rifle, carbine, or pistol tubes (with the appropriate buffer and spring). If you want to make it easy to change your configuration or don't want to have to purchase new end plates, then don't stake it.

    Soldiers use their rifles for things other than actually shooting. If someone is going to stand on your rifle, if you need to use your rifle as a pry bar, or if you plan to use your buttstock as a striking tool, by all means, stake your castle nut.

    If you go to the range, take your rifle out of the gun case, fire 50 to 500 rounds of semi auto fire, and go home. You probably don't need to stake it.
    .....unless it's parkerized under the FSB - then you must stake it ;)
    .....or you have to change the buffer tube on a 6920 - then you must re-stake it ;)

    If you go to the range and need to tell everyone how tactically ready you are for the next zombie invasion, go ahead and stake it.

    I find it hard to believe the "50 rounds to loosen" comments. I'm not saying it didn't happen. I'm just saying that the nut was probably not tightened to the spec torque to begin with.

    Now the kicker. I want you to think about all the A2 rifles out there..... rifle length buffer tubes and fiberglass stocks..... buffer tubes held on by friction....
    It's literally the pre-applied loctite on the stock screw and the stock indentation that keeps the buffer tube on. And even then, the stock usually wobbles. The only way for an A2 buffer tube to wobble off is if the tube wasn't tight to begin with. Then, you see the gap between the lower receiver and the buffer tube extension. Let it go long enough and the stock will turn right before the tube comes off. How often does that even happen? Very rarely.
     
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  18. jmorris

    jmorris Member

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    I have one that gets loose every now and then. No stake or thread locker. I just snug it up. Someday I’ll decide what stock I want on it forever and make it so.

    The threads both internal and external on everything also have a factor. Very tight thread fit will have less tendency to loosen.
     
  19. mshootnit

    mshootnit Member

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    This sort of question really breaks guys down into 2 groups. Are you a dogmatic stallwart? Are you adaptive and dynamic?
     
  20. Doc7

    Doc7 Member

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    The last couple posts about not staking don’t really make a lot of sense to me. I staked one only to unscrew and remove it a day later. You don’t have to “remove” a stake you just go Lefty Loosey and it removes itself.

    In the time it takes to post on this thread a person can stake 2-3 lowers. Why not do it??
     
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  21. C-grunt

    C-grunt Member

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    I'm for staking. It's not hard to inadvertently loosen the nut and twist the stock in your shoulder. They you run the risk of having a loose pin flopping around inside your rifle. My buddy who is an armorer has pics of a buffer pin that popped out and got wedged between the bolt carrier and the upper. Ended up splitting the upper.

    All my castle nuts are staked except for solid A1/A2 stocked rifles which have their own anti rotation mechanisms. It's not hard to do and it's not hard to undo.
     
    AndyP likes this.
  22. rbernie
    • Contributing Member

    rbernie Member

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    Oh, poppycock. :) Most folk that do not stake (myself included) ignore that step because we're LAZY - not because we're somehow dynamic and adaptive. And always remember that being dynamic just means that you're in motion - it doesn't say that you're moving in the correct direction.

    As has been said already - there is no downside to staking, other than taking 30 seconds more to finish the build.
     
    mdThanatos, C-grunt and bassjam like this.
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