30 cal Minimum bearing surface in case neck?

Discussion in 'Long Range Hunting & Shooting' started by djfergus, May 23, 2019.


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  1. djfergus

    djfergus Well-Known Member

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    What would be the minimum amount of bullet bearing surface seated into the neck of the case? 225 elds 300 Norma case? Minimum for accuracy & functionality?
     
  2. ar10ar15man

    ar10ar15man Well-Known Member

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    on magnums i have some at 220
     
  3. NEMTHunter

    NEMTHunter Well-Known Member

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    Do you single load? Or use the mag box. The shortest I have ran with no trouble is .170". Still use it with no trouble.
     
  4. djfergus

    djfergus Well-Known Member

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    I have Wyatt's, so 3.8" is max length on it. Here's my situation. We went with a .235 freebore reamer. My gunsmith told me that after reaming it that it needed an additional .060 to get the base of a 230 Berger hybrid above the shoulder & neck junction. Then asked me if I wanted him to leave it or throat it .060 more.So i said to throat it. Now it should have .295 freebore if the ptg reamer was actually .235 fb as it stated on the reamer itself. So my gunsmith tells me that I still really needed a little more freebore for those 230s as he could only get a 212 eld to seat with the base above the neck/ shoulder junction before it touched the lands. So I get the rifle home and long seat a 225 eld in a loose neck case. I close the bolt on it and it's way long when it comes out. I'm talking like won't even fit into my 3.8" long magazine and the bullet is bearly hanging on in the case. I know the rifling is not grabbing the bullet and pulling it back out. I done it again, I marked the bullet and it never moved. So, now I'm wondering if he let his throating reamer go to far. Maybe I'm missing something here.
     
  5. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    That is way to much freebore, he should of left it alone.
    May want to find a new Smith, make him set it back. 235 is plenty
     
  6. ar10ar15man

    ar10ar15man Well-Known Member

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    i think bullet shape bit him.
    but i agree see if a set back is possible
     
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  7. djfergus

    djfergus Well-Known Member

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    Yes, I thought about getting him to set it back. I originally brought the barrel, action, reamer & dummy round to his shop. He told me 2-3 weeks to do it. And he ended up taking 6 weeks, but that wasn't a problem but I don't want to wait another 6 weeks or who knows how long for him to set the barrel back. I might go with someone else to get it set back.
     
  8. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    I'd shoot it with some freebore as it sits now and see what it does. If it pukes consistently even after a couple of bullets and powders I'd start to think about a set back.
    7rum rifles are notorious for the bullet jumping... ie. being out of the case before it hits the origin of the rifling; I've had very little trouble getting .3 to .5 moa accuracy from them.
     
  9. djfergus

    djfergus Well-Known Member

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    That's what I was thinking about trying. I'm just really confused at this point about what he said he saw and what I'm seeing, am I missing something or did he miss something. I really don't take him to be a dishonest guy. Im probably going to try it. Load development really shouldn't be a chore with this rifle. Kebly Atlas tactical, 9.5 twist brux 26" sendero contour, Lapua brass. I have plenty of N570, retumbo & h1000. I'm not going to waste to much time if it doesn't show promise pretty quickly or the barrel will be getting set back.
     
  10. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    could be he was hitting throat taper too... though that shouldn't have more than a bit of taper to it...
     
  11. yorke-1

    yorke-1 Well-Known Member

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    It might shoot really well with the long jump and all work out. Or you can run it as a single shot and just seat the bullets WAY out there. You might even pick up a little extra velocity out of the deal.

    I probably wouldn't send it back to the same shop though, even if he'll do the work for free. I've used 15 different smiths for 19 different custom builds in the last 15 years and there are only 3 that I'll recommend or that I'd have do work for me again. There are a lot of well known names on my no fly list for one reason or another and I've lost a lot of time and money to learn some lessons the hard way.
     
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  12. djfergus

    djfergus Well-Known Member

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    If it happens to shoot fine, get good ES, and keep pressure moderate while achieving good velocity, what would be the draw back of jumping that far if any?
    Thanks for all of the responses.
     
  13. NEMTHunter

    NEMTHunter Well-Known Member

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    I am also jumping the 215 Berger .250" and it works great.
     
  14. Canhunter35

    Canhunter35 Well-Known Member

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    Sounds like a wby throat now.
    I’ve gotten good accuracy and with large jumps. I’d try it before setting back