Bullet Dimensional Consistency

Discussion in 'Reloading' started by Muddyboots, Oct 30, 2018.

  1. Muddyboots

    Muddyboots Active Member

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    Just starting to reach out further with my Sendero 300WM and one of the unknowns for me is how does the bullet dimensional measurement affects the longer ranges? I measure different popular 200 grain bullets and was shocked at the inconsistent bearing surface measurement I was getting. I actually gave up trying to sort them.

    So what would you expect to see in consistent dimensional measurements? Consistent bearing surface? Length? Weight? Weight ratios to bearing surface measurements? And so on? I am retired so I have way too much time on hands and maybe over thinking this concept?

    BTW - my Sendero will place 3 shots into 3/4" at 300 yards off bench if I don't drink anything with caffeine for a week.... 200 grain Accubond, 72.5 grains RL-22 (~2940 fps good ES and SD <10) and 0.010 off lands at ogive. I am changing out the RL-22 for better temp stability so carry rounds in shirt pocket to help. Off cross sticks, usually around 2" at 300 yards. I limit my shots to 500 and less just because the area I hunt rarely allows anything further anyway BUT looking at a hunt next year where I could see shots out to 700 or so. I do have access to a 1,000 yd range so looking to refine my reloading to address the possibility. What bullets can someone point to for most consistent measurement and what do you do for sorting?
    Muddy
     
  2. HARPERC

    HARPERC Well-Known Member

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    I've used and been satisfied with the 200 Accubond. It sounds like it's working for you, regardless of some of the inconsistency.

    If you're looking for consistent measurements, I think one of the turned mono-metals will provide that for you. I've been using the Hammer's, and quit sorting.
     
  3. Mikecr

    Mikecr Well-Known Member

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    I don't like to be discouraging but meaningful bullet measure and attribute consideration is really tough.
    For instance, when you suggest swings in bearing, is this really bearing at all?
    That is, are the datums on both ends of your measure qualified and isolating to just bearing, and not including ogive radius and base angle variances?
    Then, even with isolation to actual bearing, do you then expand measurement to other attributes, combining the differences for overall affect? That affect being to BC.

    As far as bearing variance itself, have you considered that affect alone? What is it?
    IMO, and given no testing that has proven otherwise, I say there is zero affect of bearing alone. It contributes nearly nothing to BC, and it does not affect pressure as is widely assumed. But test it and see for yourself (I have).
     
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  4. ShtrRdy

    ShtrRdy Well-Known Member

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    Earlier this year i was trying to understand why i couldn't get the Nosler RDF bullet to shoot well in a new 260 Rem barrel. The Sierra Matchking and Berger Hybrid worked great. I measured fron the base of the bullet to the ogive, base of the bullet to the seating stem contact, and bearing length. On the Sierra and Berger bullets I measured a maximumof 0.002" difference. On the Nosler the spread was up to 0.011".
     
  5. Axl

    Axl Well-Known Member

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    If they are shooting 3/4 @ 300 from a factory gun I would stop measuring them and keep shooting them- the only measure that maters is the target
     
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  6. gohring3006

    gohring3006 Well-Known Member

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    If you are measuring bearing surface, you need to measure case capacity, weight variation and concentricity. Because any one of those can cancel out your hard work. Shoot at 700 and see what you got. I would fix the problem when it arrives, instead of searching for it.
     
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  7. tankgijohn72

    tankgijohn72 Well-Known Member

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    SD below 10 and consistently shooting sub MOA groups at 300 yds. There is really very little that you can do to improve on that. You are ready to go to 700 yards. Best to spend the extra time practicing as opposed to chasing small variables in the reloading operation. Holes in the paper don't lie and it sounds like are already stacking them. To hit targets at longer ranges, your ability to read wind and read the relevant factors in the shot will pay bigger dividends than banging your head against the wall trying to measure the bullets/case.


    BTW - my Sendero will place 3 shots into 3/4" at 300 yards off bench if I don't drink anything with caffeine for a week.... 200 grain Accubond, 72.5 grains RL-22 (~2940 fps good ES and SD <10) and 0.010 off lands at ogive. I am changing out the RL-22 for better temp stability so carry rounds in shirt pocket to help. Off cross sticks, usually around 2" at 300 yards. I limit my shots to 500 and less just because the area I hunt rarely allows anything further anyway BUT looking at a hunt next year where I could see shots out to 700 or so. I do have access to a 1,000 yd range so looking to refine my reloading to address the possibility. What bullets can someone point to for most consistent measurement and what do you do for sorting?
    Muddy[/QUOTE]
     
  8. antelopedundee

    antelopedundee Active Member

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    Oct 14, 2018
    Maybe the bullets are made on more than one set of dies, but not kept as separate lots after that.