Okay guys I need your help!!! I have tried and tried to get my extreme spread down in the single digits and I can not obtain what I want. Usually my extreme spread on my guns is between 15-30 mostly in the upper 20s though. I'm looking for the tricks of the trade from those of you that can achieve low es with quite abit regularity. What method do you use to weigh powder charges, and what equipment? How do you get a consistent over length every time on loaded ammo? How do you get consistent neck tension? Do you weight sort all bullets you shoot and measure them from base to ogive even when you are using high quality long range bullets? Also any other important factor you have learned that helps I would be interested in hearing.
tricks to achieve low es??
- Thread starter hot range
- Start date
This is for COMPETITION loads only. I like .001 or at most .002 neck tension. I have found "generally speaking" .001 is best. Also, seating depth becomes critical not only for accuracy but also aides in lowering e.s.'s. Primers can and will make a significant difference in lowering e.s.'s too. Getting the powder charge right, for the powder you are using, makes a huge difference. Using the correct powder for the cartridge and bullet used can make a difference.
In hunting loads, you want .003+ neck tension. You're limited many times from the length of a magazine as to where you can move your seating depth to. So you may not have as many options with a hunting rifle.
In hunting loads, you want .003+ neck tension. You're limited many times from the length of a magazine as to where you can move your seating depth to. So you may not have as many options with a hunting rifle.
First thing is to determining your case capacity .
Reference. Are you putting 5 gallons of gas in a 5 or a 6 gallon tank .
Till you find that out accurate weight of powder doesn't matter .
Primer choice I would say is next .
How and where your seating the bullets is next Larry
Reference. Are you putting 5 gallons of gas in a 5 or a 6 gallon tank .
Till you find that out accurate weight of powder doesn't matter .
Primer choice I would say is next .
How and where your seating the bullets is next Larry
FeMan
Gold $$ Contributor
As said, it all matters. I hold my base to ogive measurements to 1/2 thousandths. I trickle each charge to within a granule. I anneal after every firing. For me, primers are the key though once I have everything else dialed in. For the loads I have that consistently shoot single digit ES, there is only one primer that they do that with. If I change out the primers on a sweet load, I can get ES of 20 to 30.
If you don't anneal every time, then for sure keep your batches together by the times fired. You do not want to mix 2 times fired with 3X fired for example. The neck tension changes every time you fire.
Yes, I also try to use all these tricks to make my loads more consistent.
But one important factor is being ignored here.
You have to be using a load that tunes with the barrel correctly!
When the load is properly tuned to the barrel, you will see a drop in ES that can surprise you.
I have been using a new to me method of characterizing my new barrels. After the barrel has been broken in till Mv is stable, I load 5-6 groups of 5 cases with loads that go from low to near maximum in about 1% steps. Then I shoot these cartridges in 5 shot groups in round robin fashion slow enough to preclude the barrel getting too hot. I shoot these groups at 200 yd as it is far enough to see groups and still be easy shots. I measure all shot Mv with a chronograph.
I take my targets home and the Mv data and plot the average, SD and ES for each group. I do this in EXCEL and look closest at Load vs ES and do a curve with 2-5th power polynomial curve fit. I find the low point on these curves and that is my load. If the groups size doesn't match the low ES, there are ways to calculate how much to shorten your barrel! I don't bother with that, I use a tuner for the final group tuning.
But one important factor is being ignored here.
You have to be using a load that tunes with the barrel correctly!
When the load is properly tuned to the barrel, you will see a drop in ES that can surprise you.
I have been using a new to me method of characterizing my new barrels. After the barrel has been broken in till Mv is stable, I load 5-6 groups of 5 cases with loads that go from low to near maximum in about 1% steps. Then I shoot these cartridges in 5 shot groups in round robin fashion slow enough to preclude the barrel getting too hot. I shoot these groups at 200 yd as it is far enough to see groups and still be easy shots. I measure all shot Mv with a chronograph.
I take my targets home and the Mv data and plot the average, SD and ES for each group. I do this in EXCEL and look closest at Load vs ES and do a curve with 2-5th power polynomial curve fit. I find the low point on these curves and that is my load. If the groups size doesn't match the low ES, there are ways to calculate how much to shorten your barrel! I don't bother with that, I use a tuner for the final group tuning.
Annealing and a little lube on the bullets and neck is what did it for me as far as low numbers on the ES/SD department is concerned. That said, the very next thing you discover, as so many of us have, is that low ES/SD numbers don't usually equate to terribly much better accuracy, if it contributes at all. I guess my main question for you would be: what exactly are you looking to see happen besides low numbers on the chrono when you do get the ones you are looking for????? I wish you the best of luck and I truly hope it works out the way you want it to, but I would not bet something I couldn't stand to lose on it!!!
Terry
Gold $$ Contributor
Norm
"polynomial curve fit" Are we still talking about shooting?
I'm having Gost Buster visions.
I don't want the advice to stop cause I'm learning still but I just loaded up ten rounds. I set my ribs charge master to dispense .1 gr lower then whaty target was then I trickled in one piece of powder till it jumped to my target weight. I weighed and measured all my bullets. And used some dry lube to seat them. My es was 13 fps so I'm seeing that something I did helped. Im gonna try annealing again and see what happens.
I can clear up what my goal is here also. I have a 20 br project I'm working on and im testing to see what the little gun can do at long range with 55 gr bergers. So far I havnt shot a group over .45 at 100 yards and pry 40% of the time it is in the .1s. I havn't shot it much at 500 hundred but I did one time in the wind and had 1.6 group and 2.5 group mostly horizontal. 1000 yard groups have been 5.5 and 5.7 but it's mostly all vertical, so that is why I want to perfect my es.
CaptainMal
Silver $$ Contributor
None of my past or present chronographs were worth a poop for consistency. I have never shown great ES on any crony. Have to see no vertical on the target to believe the ES is low.
Now today I watched Steve Krauss play with his LabRadar. He was not happy because of frequent "no readings". Still, when it read it was impressive with his new 7mm WSM target rifle, or whatever it was.
At one point he fiddled, got it working and showed me multiple shots with an ES of maybe 5 or so. Little bit later he showed me the 600 yard target. Not measured but my jaw dropped. Still making sure I picked it up to use. Maybe 1-1 1/2 inches with little vertical and just horizontal in kind of brisk winds.
Now today I watched Steve Krauss play with his LabRadar. He was not happy because of frequent "no readings". Still, when it read it was impressive with his new 7mm WSM target rifle, or whatever it was.
At one point he fiddled, got it working and showed me multiple shots with an ES of maybe 5 or so. Little bit later he showed me the 600 yard target. Not measured but my jaw dropped. Still making sure I picked it up to use. Maybe 1-1 1/2 inches with little vertical and just horizontal in kind of brisk winds.
Check any statistics reference an you will find most say 25 or 30 is a statistically significant sample size.
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