R700/Jewell trigger, timing issue?

Discussion in 'Advanced Gunsmithing & Engineering' started by Fast14riot, Jul 8, 2017.

  1. Alex Wheeler

    Alex Wheeler Gold $$ Contributor

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    It is normal to have to pull the bolt back a little to allow the trigger to reset on and action that has cock on close.
     
  2. fastnflat1

    fastnflat1 Silver $$ Contributor

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    So to clarify my understanding of "the whole job"...If the depth of the cocking cam helix is recut to gain optimal pin fall (.240"), then firing pin protrusion is also increased?

    Therefore you could possibly have a pin protrusion of .085" if the previous protrusion was .055"???

    So really, unless the the firing pin tip is shortened say .030", the sought after fall increase isnt gained???

    I have seen where the helix cut is deep enough but the front shoulder of the firing pin bottoms out inside the bolt first. In this case do you turn back the firing pin shoulder or bore the bolt ID deeper???
     
  3. Fast14riot

    Fast14riot Silver $$ Contributor

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    Rule #1, always modify the cheaper part. Shorten the pin before boring bolt body.
     
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  4. rayjay

    rayjay

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  5. fastnflat1

    fastnflat1 Silver $$ Contributor

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    From my recent experience...

    Protrusion DOES change!!
    After removing cock on close, you say man should re-gain that lost fall distance.... when you re-cut the cocking helix in bolt to achieve that, you are also increasing the pin protrusion by letting the pin advance farther into the bolt. Not a big deal, just modify the pin to correct it and all is well.
     
  6. Alex Wheeler

    Alex Wheeler Gold $$ Contributor

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    Firing pin stops when the collar contacts the inside of the bolt. We are not modifying this collar thus not changing protrusion. I do this for a living. It can be confusing. The helix is never deep enough on a Remington.
     
    Last edited: Jul 13, 2017
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  7. Fast14riot

    Fast14riot Silver $$ Contributor

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    I guess I should qualify the trigger, when I say second hand, I bought it with the barreled action from a member here and trust their word.

    It is clean. Cock on close means the sear and cocking piece are overlapped when bolt is cocked, until the bolt is moved aft to clear the sear, leaving some forward travel left to close the bolt completely. I have read many of Alex's detailed posts on the topic and combined with a couple more bits of info in this thread I now see fully how the system is flawed according to us, but reliable and safe according to the lawyers.

    I am not set up to cut the helix properly, but now I know exactly what must be done if I have someone other than Alex (not sure why someone other than you would be chosen, but just in case) work on my action. It's also important to me to know exactly what questions to ask a smith or if I ever pick up a used modified 700 action I can qualify it.

    Alex, thank you for sharing your hard earned knowledge on the topic.
     
  8. fastnflat1

    fastnflat1 Silver $$ Contributor

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    I fully understand the concept. I timed 2 of my own lastnight and am very pleased with the results. And yes I'm picky lol Only 1 needed the helix re-cut. It was a remington bolt, the other a PTG. Both of them had to have the collar turned back, which lead to increased pin protrusion. Simple fix though.

    The only other way to re-gain that pin fall is to shorten the other end of the firing pin and drill a new hole to pin on the cocking piece. Which most likely will shorten protrusion....

    These were remington model sevens, if it matters....

    Im not trying to start a pissing match and dont want to discount anyones knowledge, work or reputation. I found this thread interesting and after some deep thought on the subject i jumped in head first and tackled a couple of my own. I may not have done it exactly like the "professionals" but im pleased with my results and learned a bit in the process.

    Goodnight
     
    Last edited: Jul 13, 2017
  9. Jay Christopherson

    Jay Christopherson Administrator

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    If you shorten the collar, wouldn't you need to make sure that the cocking piece is not bottoming out on the bolt when the trigger releases? (I might not have the correctly terminology, but hopefully my meaning is clear).
     
  10. Alex Wheeler

    Alex Wheeler Gold $$ Contributor

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    Yes that would be one of many places to look.
     
  11. butchlambert

    butchlambert Site $$ Sponsor

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    Pretty cheap! Have you machined one?
     
  12. rayjay

    rayjay

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    That was the Midway price. The PTG price is much better :) I just remember paying about $35 for the complete PTG firing pin assy [ prolly 10 years ago ;0
     
  13. DLG

    DLG

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    So if you increase firing pin fall from .180 to .240 does that decrease pin strike energy? And if so how do you increase it and how much is enough?
     

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