Long Range Hunting Online Magazine Node...please explain
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 General Discussion Must wear red or OD green socks to participate. I can't see your socks, please be honest.

#1
04-04-2011, 11:35 PM
 Gold Member Join Date: Jan 2011 Posts: 595

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)?

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
04-07-2011, 04:56 PM
 Silver Member Join Date: Jan 2010 Location: utah Posts: 366

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
04-07-2011, 05:13 PM
 Silver Member Join Date: Aug 2008 Location: cedar rapids Iowa Posts: 236

When used with a crongraph SD stands for Standard Deviation, a statistical term.
#4
04-07-2011, 09:05 PM
 Gold Member Join Date: Jan 2011 Posts: 595

Quote:
 Originally Posted by Russ Hatch When used with a crongraph SD stands for Standard Deviation, a statistical term.
This is the SD I was referring to. Could someone elaborate???
#5
04-07-2011, 09:12 PM
 Gold Member Join Date: Jan 2011 Posts: 595

Quote:
 Originally Posted by load 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
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
04-07-2011, 09:23 PM
 Gold Member Join Date: Jan 2011 Location: Northern Utah Posts: 672

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
04-07-2011, 09:49 PM
 Gold Member Join Date: Jan 2011 Posts: 595

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

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