Arc Nuclues action owners

Schw15

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  • Jul 21, 2019
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    Posted a video of my action. Easy bolt lift then at the top it snaps open pretty hard. I talk to ARC said that was normal not saying I don't believe them or question them at all just seeing if anyone else has that samething with these actions? I'm more or less just curious.

    Arc Nucleus Gen 2 long action mag bolt face. 30 nosler but get samething on other calibers.

    My loads show no sign of pressure with primers ect. My speeds are pretty dang slow in a 30 inch barrel for that not to happen just figured I'd throw that out there since it was going to be brought up.

    Once again just more or less curious if others see this with those actions across the board.
     

    spife7980

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    It sounds like the brass dragging in the chamber and it then engaging the primary extraction ramp and not the action itself to me.
     

    Ledzep

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  • Jun 9, 2009
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    Cases are sticking in the chamber and you're having to engage the primary extraction cam. It's a case/pressure/chamber thing not the action.
     
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    Schw15

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  • Jul 21, 2019
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    I was thinking maybe the dies wasn't resizing the case enough at case head with .002 shoulder bum. Pressure not much there no signs in primer or no heavy bolt lift. I can open bolt easy to the top. My speeds are in the 2860 to 2900 for 230 a-tips 30 nosler and 30 inch barrel.

    But send videos to ARC they said it was nor.al but just wanted to see others experiences
     

    Schw15

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  • Jul 21, 2019
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    Hi Scott,

    The hang-up at the top does seem to be a normal function of the action when brass is stuck in the chamber. The Nucleus uses bolt-cam extraction, so what is happening is that when you are getting near the top of the bolt lift, the handle of the bolt is hitting the angled surface at the back of the receiver to simultaneously pull the bolt open and back to get the case out. Please let me know if you have any other questions.

    Thank you,

    From ARC
     

    Schw15

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  • Jul 21, 2019
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    Clickers either need new dies custom dies or polish out chamber maybe I guess. Ran into this twice the past few years before that the last 15 years nothing like this
     
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    AllenOne1

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    Consider ordering a die from Whidden or better yet if you have time send them fired brass and have them make you a custom sizing die. Their standard die will most likely fix your issue.
     

    RFutch

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    Mine does it sometimes but has gotten better. Seemed to to it worse on new brass than fired a couple times.

    I thought initially is was pressure but my loads in that rifle are not near the top end so I kinda forgot about it.
     

    Schw15

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  • Jul 21, 2019
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    Consider ordering a die from Whidden or better yet if you have time send them fired brass and have them make you a custom sizing die. Their standard die will most likely fix your issue.
    They don't make a 30 nosler die have to be custom
     
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    Schw15

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  • Jul 21, 2019
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    Mine does it sometimes but has gotten better. Seemed to to it worse on new brass than fired a couple times.

    I thought initially is was pressure but my loads in that rifle are not near the top end so I kinda forgot about it.
    So yours does that all the time as well?
     

    RFutch

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  • Sep 28, 2010
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    So yours does that all the time as well?
    Not anymore. Prob have 500 rounds on the action now with 3 different barrels for it. It probably hasn't done it in the last 200-300 rounds.
     

    Schw15

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  • Jul 21, 2019
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    Not anymore. Prob have 500 rounds on the action now with 3 different barrels for it. It probably hasn't done it in the last 200-300 rounds.
    Strange. Mine has prolly 2k or more on it. Mine does it more when the brass gets older
     

    spife7980

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    Strange. Mine has prolly 2k or more on it. Mine does it more when the brass gets older
    As expected. It’s a vivacious cycle.
    The older the brass gets the more it has been fired and sized.
    The more it gets fired and sized the harder it gets as a result of the work done to it.
    The harder it gets the more it wants to spring back opposite to sizing so it won’t get smaller and it will get larger while resisting the sizing die.
    So you need to find a die that sizes down more still to overcome the spring back or you need to open the chamber a smidge to allow your current die to be enough sizing that it springs back away from the chamber after firing towards its sized state.
    Sounds like right now it’s more tangential contact between the die and the brass coming out of it but some dimensional numbers for the brass sized-loaded-fired for each cycle of its life would be helpful in tracking this sort of issue.
     

    Schw15

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  • Jul 21, 2019
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    As expected. It’s a vivacious cycle.
    The older the brass gets the more it has been fired and sized. The more it gets fired and sized the harder it gets. The harder it gets the more it wants to spring back opposite to sizing so it won’t get smaller and it will get larger while resisting the sizing die.
    So you need to find a die that sizes down more or you need to open the chamber a smidge to allow your current die to be enough.
    I have found ADG brass to do this more than others. But yeah I'm afraid so. The die might be harder I think a good polishing be easier cheaper and faster
     

    Schw15

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  • Jul 21, 2019
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    So the reamer specs should be .5510 at .200 line 30 nosler my brass fired is .548 to .549 sized I belive .548 .5475