Node...please explain

Discussion in 'General Discussion' started by shortpants, Apr 4, 2011.

  1. shortpants

    shortpants Well-Known Member

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    Hey guys and gals just wondering if someone can help me make some sense of a couple of terms I see being used a lot on here.

    Node, as in finding the node?

    SD, I've seen used with along with ES (extreme spread I get)?

    Killing critters at 1300+ yards??? Please help me with this one especially!!!:D

    I love this site and spend way to much time on here but can't get enough. I'm thirsty for knowlege and you guys are great teachers!
     
  2. load

    load Well-Known Member

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    accuracy node typically means a point were the barrel whip is at top dead center (still point) AND harmonics from case expansion is at the rear of the action. if the bullet leaves the barrel when this vibration is at the front the vibration will be transfered to the bullet and it will fly horrible.
    sd is sectional density or how much a bullet wieghs per calibler
    es is extreme spread the difference from shot to shot
     

  3. Russ Hatch

    Russ Hatch Well-Known Member

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    When used with a crongraph SD stands for Standard Deviation, a statistical term.
     
  4. shortpants

    shortpants Well-Known Member

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    This is the SD I was referring to. Could someone elaborate???
     
  5. shortpants

    shortpants Well-Known Member

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    Thanks for the reply, I knew it was something to do with barrel harmonics but that's all I knew. The SD I was referring to was Standard Deviation. Still trying to figure out what excactly that means???

    Thanks for helping out a rookie guys I sure appreciate it!!!

    One more question. How do you control the timing to find your node, adjust the charge?
     
  6. Browninglover1

    Browninglover1 Well-Known Member

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    ES is a statistical term and is the difference in velocity between your fastest shot and slowest shot. The lower the ES the more consistent your velocities get.

    Standard Deviation is used in much the same manner but it shows how far away from your average velocities you can expect most of your shots to be. Just like ES a low SD usually produces the best accuracy. It's kind of hard to explain without using formulas and graphs but here's a link that I used to understand the terms myself when I was taking a statistics class a few semesters back.

    Standard deviation - Wikipedia, the free encyclopedia
     
  7. shortpants

    shortpants Well-Known Member

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    Thanks that helps. Is it possible to have a low ES but high SD?
     
  8. Russ Hatch

    Russ Hatch Well-Known Member

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    The lower the ES the lower the SD. Reloaders strive for a SD below 10. If you have a string of shots with velocities very close together the round should be very accurate at long range as the barrel vibration patterns will be very simular which if you have the velocity at an node is a very good thing.
     
  9. shortpants

    shortpants Well-Known Member

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    So when you finally get your SD below 10 and your ES below 20 ( I've heard that's the goal, preferably less) How do you get the bullet to leave the barrel at the right time so that all the stars line up? I thought it was hard enough to find the perfect load but now your telling me I have to have my bullet leave the barrel at a particular time. You guys are asking a lot!:D

    Thanks again for helping this simple mind try and make sense of a complicated process! I LOVE THIS STUFF!!!
     
  10. RDM416

    RDM416 Well-Known Member

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    I assume this was a serious question so I will treat it as one........ It simply means what it says. There are quite a few guys on this site who are capable and have killed game animals at 1300 yards and well beyond. Personally, I have killed several deer at ranges from just a little over to just a little under 1000 yards. At this point around 1000 yards is my self imposed limit. That is the max range I feel confident in making a first shot vital area hit. Terrain and conditions can and often do decrease the range I am willing to take a shot considerably.

    Keep in mind that most of the guys "killing critters at 1300+ yards" are not taking "poke and hope" shots. They have skill and equipment to be confident they will make the hit in the given conditions or they pass on the shot.
     
  11. shortpants

    shortpants Well-Known Member

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    I appreciate your response and live by the very same principles as you. I have to admit there was a little sarcasim in that part of my question but the reason I ask these questions is in fact to gain the knowlege and confidence as you 1000+yard guys. I know there is no magic that is going to turn me into the shooter I hope to be but great information and my ability to apply that info will get me there someday. I have shot out to 1000 many times but my self imposed 1 shot 1 kill limit is 500 for now. My goal for this year is to extend that to 700-800. You guys are helping me achieve my goals and I'm very greatful!
     
  12. shortpants

    shortpants Well-Known Member

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    Anyone have a link to ladder testing. I think this stuff is starting to make some sense!:)
     
  13. RDM416

    RDM416 Well-Known Member

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    You should be able to find quite a bit about ladder testing from a search, there have been several good threads on that in the last few years.

    You are doing an important part of what it takes to become a LR shooter. I often run into guys at hunting camps around the country and when shooting at 500 to 1000 comes up, a common statement will be "you must be a really good shot"......... some say this with a little respect others with a little sarcasm.

    My response is normally the same....... shooting long range is not about being a "good shot" (at least not in the way they are thinking) It is about "knowing how" and having the equipment that makes such a shot possible.

    For example; I was at a 4-H rifle coaches training program a few weeks ago. Several of the people there know me and know how much I shoot LR. When we got started shooting (.22s standing, sitting, prone (no rest)) they expected me to just clean up. I did OK but several were obviously "better shots" than me and had much less shooting experience, but give me "my rifle" with "my gear" shooting the way I want to shoot and anything within a 1000 yards is in trouble. Those same people who "ate my lunch" shooting .22s at 50 yards standing would not even know where to start to make a 1000 yard shot......so who is the better shot???

    The old mantra of "practice, practice, practice......" is important, but with LR shooting "practice" is just burning ammo if you don't "know how" and and have the proper equipment. Keep learning, you are on the right track, asking the right questions:)
     
  14. shortpants

    shortpants Well-Known Member

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    Thankyou very much for the reply, you just described what I have been doing for 15 years. I have burnt up a lot of money and time which I don't consider wasted at all but I finally realized I needed to learn the science behind LR shooting if I am ever going to be a confident 1000 yd. shooter.