Where to start seating A-Max and SMK?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by JARHEAD1371, Sep 21, 2010.

  1. JARHEAD1371

    JARHEAD1371 Well-Known Member

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    I've decided to try the 162 A-Max and 175 SMK out of my 7SAUM for antelope and deer. I've been shooting Berger's loaded into the lands. Where should I start loading the A-Max and SMK? I've searched as much as I can on this subject and haven't turned up much about COAL. Thanks for any info.
     
    Last edited: Sep 21, 2010
  2. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    IMO go with the AMAX. Seat to mag length and tune with powder and primers. COAL does not effect amax.
     

  3. Varmint Hunter

    Varmint Hunter Well-Known Member

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    I have found the A-Max bullets to be very accurate in several of my rifles. I typically get good accuracy between .010"-.020" off the rifling. I don't ever recall loading them to max magazine length because the A-Max is very long and would protrude deeply into the case. However, if that length will work in your rifle than it's certainly worth a try.
     
  4. elkaholic

    elkaholic Well-Known Member

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    The A-Max is a secant ogive bullet and NORMALLY likes to be seated at or near the lands. Most of the SMK's I've shot like to be .010-.020" off but every rifle is different. Good luck.....Rich
     
  5. NZ Longranger

    NZ Longranger Writers Guild

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    Elkaholic is on the money in my experience. We start with A-Max's Just touch and SMK's jumping 20 thou, then tune from there.
    Greg
     
  6. arthurj

    arthurj Well-Known Member

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    My .280 likes the 162 .002" in the lands.
     
  7. Rocky Mountain

    Rocky Mountain Well-Known Member

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    If you wont a mag fed round then the SMKs would be my first bet as they are very forgiving seating depth wise. Otherwise start just on the lands for both then test.
     
  8. jrw1976

    jrw1976 Well-Known Member

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    What do you guys start with as a normal seating depth when you are trying to work up a new load. Do most of you start at the lands and work back or do you start with a certain jump measurement and work around that to tune. I have only been reloading for about 6 months and this is one of the things that I ponder over. Thanks Jason
     
  9. elkaholic

    elkaholic Well-Known Member

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    There is some good starting info in the above posts. VLD's near or into lands and tangent ogives (spitzers) about .020" off. Some folks have had some luck seating the VLD's quite a ways off the lands and not paying too much attention to the 100 yd. groups but checking the accuracy at longer ranges. TEST TEST TEST! That's why we have lots of good barrel makers:)....Rich
     
  10. Mikecr

    Mikecr Well-Known Member

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    I pick a moderate load(nothing extreme) and adjust to determine best seating first.
    Then go to powder adjustments.

    I know of no reason that seating rules of thumb would hold from one gun to another(unless the same reamer was used). Seemingly forever shooters declared jammed as best for VLDs, -until Berger debunked this. Now people aren't so afraid of 'evil' VLDs.
    But if you WANT your seating at some particular value, you can of course tweak powders to get the best THAT seating will produce for you.
    I suspect this is most common...

    My opposite approach on this is based on experience with one gun long ago. And it's worked with every other since.
    One powder optimum seating point, held for another powder, and another. Even though velocities and performance(tune) were completely different between them, best seating point still held as best -for that chamber.
    So I strongly feel that seating is not a tuning tweak at all, but a prerequisite to potential performance.
     
    Last edited: Sep 23, 2010
  11. Varmint Hunter

    Varmint Hunter Well-Known Member

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    If you want a rifle that can feed from the magazine then I'd start there. You would be surprised at just how many rifles shoot good groups at .100"-.200"-.300" off the rifling. I have a custom .308 that I was working up loads for. I really don't care about feeding from the magazine but just for the heck of it I loaded some 165gr Accubonds to fit in the magazine. They were .125" off the rifling. To my surprise it was the most accurate load for that bullet in that particular rifle. A-Max bullets hated it that far off but the Accubond was at its best at a full 1/8" off the rifling. Go figure.
     
  12. NZ Longranger

    NZ Longranger Writers Guild

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    Yes, the forgiving tangental ogives like the AB or SMK can often work surprisingly far off the lands. But in my experience, rarely do secant ogives like A-max's and Bergers shoot good groups jumping very far at all, and the VLD's shoot best more often than not around 10 to 15 thou into the lands. This is at 100 yards anyway, but as Elkaholic and others have said, the VLD's may shoot ok further out even if not too flash at 100 yards. Its just much easier doing your initial load development at 100 yards, then going back to 600 and 1000 yards to confirm what you're seeing at 100. Occasionally you'll get a load that performs good at 100 that looses it further out and vice versa, but this is the exception. Usually a load that groups great at 100 yards with a low ES will work great at long range.
    Greg
     
  13. elkaholic

    elkaholic Well-Known Member

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    Again, this is an example of tangent vs. secant ogive. The secant (more often than not) likes to be close or into the lands.......Rich
     
  14. Mikecr

    Mikecr Well-Known Member

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    Can you provide a basis for this? A logical reason?
    I wonder, because I've never seen one.

    Why does ANY bullet 'like' one seating over another, in a particular chamber?