Weighing bullets,,,does it make a difference

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by GNERGY, Jul 17, 2010.

  1. GNERGY

    GNERGY Guest

    Do you guys weigh bullets into groups and does it make any difference. I'm NOT looking for another step to go through during the loading process.
    In one of the threads about loads for a 25-06 somebody mentioned weighing Speer TNT bullets that 400 would get him 200 good bullets.
    When I built my 25-06 I was using once fired mixed lot military brass and Curry bullets and shot 5 shot 1/4 inch groups at 100yds.

    I know the Barnes .338 225gr TTSX bullets aren't exact weight, they vary some. But I can put 3 touching at 300yds. Would sorting them make the groups better? ( each group would use bullets of exact weight )

    Or are we talking about a needle in a haystack?
    And don't forget about human error when trying to hold the gun steady and squeeze off those shots all in the exact same place.

    I guess a rail mounted bench gun would tell the difference.
    You guys shootin these 2 to 3 inch groups at 600 yds what are you doing/
    Tarey
     
  2. nfhjr62

    nfhjr62 Well-Known Member

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    Didn't think so BUT at longer rangers it looks to be the way to go
     

  3. Mikecr

    Mikecr Well-Known Member

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    Hard for me to imagine bullets with enough weight variance to make any difference at all..
     
  4. royinidaho

    royinidaho Writers Guild

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    My experience is that weight difference corresponds to bearing surface difference when relates directly to variations in velocity.

    I would suppose that sorting by bearing surface length would be more fruit full.

    Then add meplat trimming and repointing and one begins to ask where the fun went.:rolleyes:

    I have a load in a 338 RUM that shoots lights out at 300 yds. However with its 50-60 FPS extreme velocity spread its pretty much useless for yotes and maybe even deer beyond 700 yds. My steel coyote, full size, was pretty save at 830 yds.

    I've calculated, hopefully correctly that an ES over 15 with a high bc bullet will cause misses at yote @ 1000.

    I don't do any of the above things. I used to when shooting benchrest but my LRH rifles out shoot any bench rest rifle I had. And I had some good ones.
     
  5. Chas1

    Chas1 Well-Known Member

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    Alot of BR guys weigh em but matches are won and lost on tenths of inches or less and extreme consistency is critical. I'd imagine some LR hunters sort and some don't, I don't.
     
  6. loaders_loft

    loaders_loft Well-Known Member

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    if you want to sort bullets, sort by bearing surface not weight. The bearing surface affects pressure buildup inside the barrel (more surface, more pressure, more velocity). It goes pretty quick with a sorting tray and calipers with two comparators, attached closely to the base of the caliper blades.

    After about 200 measurements I decided to quit sorting lapua 139 scenars. There was no variation to 3 places

    I recently sorted couple boxes of swift scirrocos (150gr .284 and 130gr .264). On the 130's, 97 of 100 were within .001 and on the 150's, 97 of 100 were within .002. That is very good, I think I won't sort any more scirrocco's either.
     
  7. Buffalobob

    Buffalobob Writers Guild

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    I imagine it makes a difference. :D

    [​IMG]
     
  8. Chas1

    Chas1 Well-Known Member

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    For your money it looks like they might a thrown a little more lead into the 6th f/left:D
     
  9. sniperjwt

    sniperjwt Well-Known Member

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    Whats the BC of that one?:rolleyes:
     
  10. jimbires

    jimbires Well-Known Member

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    gas powered meplat trimmer ???
     
  11. woods

    woods Well-Known Member

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    x2

    Best check the bearing surface of all the Accubonds you reload for, I find significant variations in those
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    but like loaders loft I found very little variation in the 130 gr 6.5 Scirroccos or any of the other bullets including Barnes TTSX's, even thought the TTSX did vary a lot in weight.

    225 gr TTSX's grouped in .1 gr weight difference from 224.1 gr upper left to 225.7 gr lower right
    [​IMG]

    but the bearing surface was within .003" so they seemed to shoot well. IOW, I was never able to tie any accuracy problems to weight variation.
     
  12. Mikecr

    Mikecr Well-Known Member

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    As an example:
    1/2 of a grain off from a 190smk = .002change in G1BC = .5"@1000yds[.048moa]..
    The MV change of ~4fps counters this almost exactly though..
    That is, if the bullet is low by 1/2gr, it's BC drops, but it's MV rises to counter.
    So nothing to account for there really.

    As far as any assumed dimensional changes with weight variance,, well, is it so wise to assume anything? And you cannot measure bearing surface variance without first qualifying the ogive radius(your datum). That is, unless you just want to assume that as well..
    More wasted efforts..

    Anyway, I highly doubt that bullet weight consistency has contributed to any BR shooters success, or failures.
     
  13. Coyboy

    Coyboy Well-Known Member

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    Tarey, I have a customer who is a nationally competative f-class shooter.
    He buys 2000 bullets at a time and sorts them by weight and bearing surface.
    When he is done he has over 40 boxes of bullets. Long and time consuming but he feels it is well worth it for his dicipline

    The small quantity batches are used for fouling rounds.

    The larger batches that have enough for a match he will load together for an individual match or range session.

    He was at Lodi during a wind clinic, they were set-up to shoot a 5 shot group so the instructors could asess everyones equipment, before the serious work began. John shot his 5 rounds into a group that measured 1.5" of vert. and 2.75" of horz. at the 1000 yard line. Just so happens they were all in the x ring.
     
  14. Mikecr

    Mikecr Well-Known Member

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    Did your customer ever validate his efforts?
    Or is it pure delusion?