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Es and sd numbers
#8104873
12/27/20 08:40 PM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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I'm new to having a chronograph, and don't really know how to read es and sd numbers to tell if I'm consistent or not. Yes, I understand that the smaller the number on both the better, but, are my numbers a good start?
6.5 cm, 42.3 h4350, 143 eldx
2799 2768 2780 2765 2761 Ave = 2775 Es=39 Sd = 13.75
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Re: Es and sd numbers
[Re: unclebubba]
#8104877
12/27/20 08:56 PM
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Joined: Dec 2008
Posts: 43,112
J.G.
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Not bad.
ES 20 or less is my goal.
What scale are you using?
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Re: Es and sd numbers
[Re: J.G.]
#8104897
12/27/20 09:26 PM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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Not bad.
ES 20 or less is my goal.
What scale are you using? Im sure the scale why my es isn't lower than it is. ![[Linked Image]](https://texashuntingforum.com/forum/pics/userpics/2020/12/full-31921-271783-screenshot_20201227_152344_chrome.jpg) I should probably go back to my slide scale if I want better numbers.
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Re: Es and sd numbers
[Re: unclebubba]
#8105071
12/28/20 01:06 AM
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Joined: Dec 2008
Posts: 43,112
J.G.
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Most likely.
I apologise ahead of time. Check that scale against a beam scale. If you don't have a beam scale, get one. Load up another 5 shot group on the beam scale and report back.
My Charge Master has a +.15 to -.15 gr error. Loading on a beam scale dropped my ES, in 7mm-08 to 10 fps.
And now I use an Autotrickler to .02 gr.
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Re: Es and sd numbers
[Re: unclebubba]
#8105076
12/28/20 01:11 AM
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Joined: May 2011
Posts: 2,114
TAB
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Using some graphite powder on the neck when you seat your bullets with take that es/so right on down too. Check https://www.midwayusa.com/product/1012767842Works like a champ, especially if you do bushing dies and .002” neck tension.
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Re: Es and sd numbers
[Re: unclebubba]
#8105099
12/28/20 01:28 AM
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Joined: Dec 2013
Posts: 7,868
GasGuzzler
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Your Standard Deviation is pretty good in my book. Your Extreme Spread is not bad but can be improved.
ES and SD are not reloading specific. They are terms of probability. Any math major can explain.
Pass the gravy.
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Re: Es and sd numbers
[Re: GasGuzzler]
#8105170
12/28/20 02:41 AM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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Your Standard Deviation is pretty good in my book. Your Extreme Spread is not bad but can be improved.
ES and SD are not reloading specific. They are terms of probability. Any math major can explain. Yes, I understand the mathematical terms and what they mean. I was asking for interpretation on how good or bad those numbers are when compared to other handloader's numbers. Also would be curious how they compare to some factory numbers.
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Re: Es and sd numbers
[Re: J.G.]
#8105171
12/28/20 02:42 AM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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Most likely.
I apologise ahead of time. Check that scale against a beam scale. If you don't have a beam scale, get one. Load up another 5 shot group on the beam scale and report back.
My Charge Master has a +.15 to -.15 gr error. Loading on a beam scale dropped my ES, in 7mm-08 to 10 fps.
And now I use an Autotrickler to .02 gr. Apologize for what? I do have a beam scale. I just have been too impatient for a beam scale.
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Re: Es and sd numbers
[Re: unclebubba]
#8105173
12/28/20 02:45 AM
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Joined: Jan 2009
Posts: 20,335
Judd
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If it shoots well, I’d watch it and be looking at things that could be causing the first shot because it is the bad one, the rest of them were acceptable in my mind.
When I am looking for ES/SD improvements I always look first in two areas largely suspect...neck tension and primers.
Don't let your ears hear what your eyes didn't see, and don't let your mouth say what your heart doesn't feel As much as I hate to admit it, I do like my truck
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Re: Es and sd numbers
[Re: Judd]
#8105194
12/28/20 03:03 AM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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If it shoots well, I’d watch it and be looking at things that could be causing the first shot because it is the bad one, the rest of them were acceptable in my mind.
When I am looking for ES/SD improvements I always look first in two areas largely suspect...neck tension and primers. Yes. Cold bore shot is high and left of the rest of the group. At 200 yards, it was a 3", 5 shot group. Take the first shot out, and it was a 1.5" group. 100 yard group is about .5".
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Re: Es and sd numbers
[Re: unclebubba]
#8105401
12/28/20 12:58 PM
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Joined: Dec 2008
Posts: 43,112
J.G.
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Most likely.
I apologise ahead of time. Check that scale against a beam scale. If you don't have a beam scale, get one. Load up another 5 shot group on the beam scale and report back.
My Charge Master has a +.15 to -.15 gr error. Loading on a beam scale dropped my ES, in 7mm-08 to 10 fps.
And now I use an Autotrickler to .02 gr. Apologize for what? I do have a beam scale. I just have been too impatient for a beam scale. It will get in your head knowing you can make excellent ammo, but it is slow to make.
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Re: Es and sd numbers
[Re: unclebubba]
#8105543
12/28/20 03:21 PM
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Joined: Jun 2011
Posts: 37,473
Buzzsaw
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If it shoots well, I’d watch it and be looking at things that could be causing the first shot because it is the bad one, the rest of them were acceptable in my mind.
When I am looking for ES/SD improvements I always look first in two areas largely suspect...neck tension and primers. Yes. Cold bore shot is high and left of the rest of the group. At 200 yards, it was a 3", 5 shot group. Take the first shot out, and it was a 1.5" group. 100 yard group is about .5". wait what?
SPACE FOR RENT
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Re: Es and sd numbers
[Re: J.G.]
#8105836
12/28/20 07:09 PM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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Most likely.
I apologise ahead of time. Check that scale against a beam scale. If you don't have a beam scale, get one. Load up another 5 shot group on the beam scale and report back.
My Charge Master has a +.15 to -.15 gr error. Loading on a beam scale dropped my ES, in 7mm-08 to 10 fps.
And now I use an Autotrickler to .02 gr. Apologize for what? I do have a beam scale. I just have been too impatient for a beam scale. It will get in your head knowing you can make excellent ammo, but it is slow to make. Oh, now I understand. LOL. Thanks!
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Re: Es and sd numbers
[Re: Buzzsaw]
#8105840
12/28/20 07:12 PM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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If it shoots well, I’d watch it and be looking at things that could be causing the first shot because it is the bad one, the rest of them were acceptable in my mind.
When I am looking for ES/SD improvements I always look first in two areas largely suspect...neck tension and primers. Yes. Cold bore shot is high and left of the rest of the group. At 200 yards, it was a 3", 5 shot group. Take the first shot out, and it was a 1.5" group. 100 yard group is about .5". wait what? The cold bore shot (first shot) was high and left, making my 200 yard group a 3" group. If you took the cold bore shot out of the equation, the group was a nice round 1.5" group at 200 yards. Or, are you saying "wait...what?" to Judd?
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Re: Es and sd numbers
[Re: unclebubba]
#8105851
12/28/20 07:25 PM
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Joined: Oct 2004
Posts: 40,619
redchevy
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Your Standard Deviation is pretty good in my book. Your Extreme Spread is not bad but can be improved.
ES and SD are not reloading specific. They are terms of probability. Any math major can explain. Yes, I understand the mathematical terms and what they mean. I was asking for interpretation on how good or bad those numbers are when compared to other handloader's numbers. Also would be curious how they compare to some factory numbers. Wont claim it is representative of all factory ammo as i am sure some is better than others and some are luckier than others. I fired this string of 6 factory loads over the magnetospeed a while back. While the on paper results are less than stellar it holds about MOA at 100 yards. I killed a doe with it this season for kicks and if your not into long range precision it will likely suit most peoples needs just fine. Only handload I have anything recorded on is a 4 shot group with the load I settled on with my 7mm08. Hornady 175 ELDX, 43.2 Grains of H-4350. Max - 2613 Min - 2607 Average - 2610 ES - 6 SD - 2.75 I don't know how it will hold up to that for the long run, 4 rounds is a very small window lol. I haven't had the chronograph back on it since then though.
Last edited by redchevy; 12/28/20 07:34 PM.
It's hell eatin em live
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Re: Es and sd numbers
[Re: unclebubba]
#8106542
12/29/20 01:09 PM
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Joined: Apr 2010
Posts: 6,219
dee
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If you're in the middle of a solid wide accuracy node es/sd with single digit numbers is pretty easy to achieve.
"A vote is like a rifle; it's usefulness depends on the character of the user" Theodore Roosevelt
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Re: Es and sd numbers
[Re: redchevy]
#8108296
12/30/20 07:35 PM
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Joined: Nov 2011
Posts: 10,920
unclebubba
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. Wow. That's terrible. Makes me feel a lot better about my 39 ES
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Re: Es and sd numbers
[Re: unclebubba]
#8117942
01/06/21 08:21 PM
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Joined: Jan 2021
Posts: 9
swampbug
Green Horn
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Green Horn
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OK, ES/SD can be looked at many different ways. Start with, what am I trying to achieve. If you are hunting or shooting paper under 300 yards, your ES/SD can be a lot bigger than say if you trying to shoot out to a 1,000 yards. Under 300 yards you are still gonna hit what you shoot at. May not be the tiniest groups but you are still gonna hit it. Out to 1,000 yards or more, you are gonna have problems with consistent hits and/or small groups. If you have a ballistic calculator and understand MOA/MIL, plug in 2 different velocities at a 50 FPS difference and see what your drop is at 1,000 yards. It can easily mean a hit or no hit. If you are reloading to improve precision over factory ammunition, your ES/SD a numbers are not good. Those are basic factory ammunition numbers. With a 6.5 CM, 4350 powder , and a 143 ELDX (all good components) you should easily be able to achieve less than 20 ES (hopefully 15ish) and single digit SD. A 6.5 is actually easy to tune. One tip, and this assumes you are doing a lot of the other stuff correctly, if your ES and SD are high, then you have a powder charge problem. You need to learn how to run a powder charge test to look for velocity nodes. 3 different loads in a row that give you basically the same velocity. That should solve your ES/SD numbers. Then if ES/SD numbers look good but your groups are not the best, you have a seating depth problem. So based on the optimal powder charge you found, you shoot 3 shot groups at different seating depths. Example would be if you started off at .020 off the lands, load 10 groups of 3 at .003 deeper and deeper. So .020, then .023, then .026, etc . Shoot these and compare the 10 groups. Hopefully you will see where the groups may start out big by slowly tighten up as you go shorter and then they will hit a point where the groups will actually start to get bigger. Again, you would try to find 3 consecutive groups that give you basically the same group size. This would be your optimal seating depth. This a very broad answer. Reloading needs to meticulous to achieve precision loads and there are many opinions on how you get there and what it all means. There is a lot of good Youtube to watch on this stuff. Google up Erik Cortina or Bolt Action Reloading or Ultimate Reloader or Texas Precision. All have good videos on reloading
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Re: Es and sd numbers
[Re: unclebubba]
#8118076
01/06/21 10:00 PM
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Joined: Jun 2009
Posts: 4,336
Korean Redneck
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To defend factory ammo a little, I have chronograph-ed a 5 shot of the ubiquitous 168 and 175 Sierra Matchking in 308 by Federal GMM and has SD/ES closer to like 15/35 fps. But then once in the same box the next set did something like 2.5 times as bad. Once I get an order from Custom Reloads of Dallas, then I'll report back how good (or bad) his "factory ammo" performs.
I'll say this much from my small sample set. it does seem like 20ish sd and/or 40ish es is a good mark. I know the loads I've tried that get over that do not do well. However, I can't really tell the difference on paper between loads that get 5 like vs 15 fps for sd's with my limited shooting ability. I mention that because to me the grouping in the main point and u may get lost in the weeds of chasing numbers. I totally did when i first got my chronograph. I actually use that thing much less now. After some initial load testing and getting a solid load, try to see if what i like on paper before I try to chase numbers further.
I'm a dude who likes long barrels!
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Re: Es and sd numbers
[Re: unclebubba]
#8118261
01/07/21 12:20 AM
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Joined: Jan 2021
Posts: 9
swampbug
Green Horn
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Green Horn
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20ish sd and/or 40ish es is a good mark - again it depends on what you are trying to achieve. If you are trying to improve your rifles precision by reloading , it is not good. If all you care about is hitting paper at 100 yards, to each his own. if you care about hitting steel at a 1,000 yards, it is not good. Example/math 6.5CM 140gr Berger HT H4350 ES of 50 Dope for 1,000 yards at 2,730 Velocity - 30.3 MOA Dope for 1,000 yards at 2,780 velocity - 29 MOA So with an ES of 50 that gives a difference in elevation of 1.3 MOA or 13 inches between the 2 shots. You just missed the target and have no idea why. Don't get me wrong, the lowest ES/SD is not always the best or guarantee hits. The OP simply asked if his numbers are a good start which implies that he wants to do better. He can do better
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