Thread: HOW IMPORTANT IS ES

How important is ES and does it mean you have an accurate load?
Just working up loads for a 6.5x55 130 accubond at 2900 with an ES of 5 ,130 scirocco ES of over 20 both loads 3 shots into a ragged hole at 100 . Can't get a lower ES with the scirocco any idea why?

Pretty sure an ES of 20 is considered good.
The big test would be if the groups started opening up at long range, 1km type stuff.

I'd be more than happy with ragged hole groups and an ES on 20.

ES is only really important if you are shooting long range. Most of the cheaper chronos aren't accurate enough to for you to be able to get reliable ES data, average speed yes, but ES no.
One way to improve ES is to get consistent neck tension. Shawn Carlock mentioned that lubing the inside of the case neck with graphite improves ES. Get a container, put some lead shot in, put some graphite powder in, push the sized case down into the container, inside case neck lubed.

you probably wont notice velocity spread on a target at 100 if both the loads group the same, you need to run through a chrony. the only other way is to shoot targets at a bit of distance

loads were run through a oehler 35.

Originally Posted by stug

ES is only really important if you are shooting long range. Most of the cheaper chronos aren't accurate enough to for you to be able to get reliable ES data, average speed yes, but ES no.
One way to improve ES is to get consistent neck tension. Shawn Carlock mentioned that lubing the inside of the case neck with graphite improves ES. Get a container, put some lead shot in, put some graphite powder in, push the sized case down into the container, inside case neck lubed.

Here are the sort of things to consider in getting consistent neck tension
Neck Tension — Not Just Bushing Size within AccurateShooter.com
The graphite lubing works reasonably well after cleaning cases with ultrasonics.

Originally Posted by von tempsky fan

loads were run through a oehler 35.

Your ES values will be good then. Sometimes a change of primer can help ES

Not sure why, but I've always used SD rather than ES as a measure for reloading quality control. Once you get into single digit figure SD for 5 or more shot groups, your ammo is pretty decent.

Will be interesting to hear other folks opinions on SD vs ES.

I will try a different primer with the sciroccos and graphite lube the necks it should be interesting to see results.

The value of ES is knowing the worst case scenario, so this applies particularly to long range target shooting. A load with a reasonable SD will put most into tight elevation at long range BUT if the ES is bad, the odd shot will cop a bad score and it's nothing to do with your trigger pulling or wind calling. Serious target shooters can't live with that.

Your average deer shooter can happily ignore either metric and if they get a half reasonable group, they will easily put meat on the table.

ES or SD means shit if it won't group, I've had single digit loads shoot like crap & 20-30fps ES loads shoot mint, go figure....

Kirby reckons 20-40 fps ES you are GTG if any one should know it will be him if you are hunting.

Obviously in this case less is more, but isn't necessarily necessary...

I'd be happy with that.

Have a read of this guy's experience Shooting Australia - Canada 2002
Fair way thru he documents his long range load ES and SD. Doesn't weigh his charges, in fact cannot say how many grains - uses Harrell dispenser.
Shooting a minscule groups at 100yds can mean zip at long range. Litz has also covered off on the same topic.
Shot a few .15 groups with my 6.5x47 at 100yds but didn't even progress with the load to actual long range shooting as the ES was around 30fps.
Small ES means minimal vertical dispersion at long range.
Mute point obviously for hunting type accuracy requirements.
Chronograph some brands of factory ammo and the ES is shocking but then so is the accuracy.

Originally Posted by ebf

Not sure why, but I've always used SD rather than ES as a measure for reloading quality control. Once you get into single digit figure SD for 5 or more shot groups, your ammo is pretty decent.

Will be interesting to hear other folks opinions on SD vs ES.

Well here is something interesting, I just got a chrono so used it Friday. Only 5rnds as an initial trial so have to be careful reading too much into them.

I dont think much of SD as a quality control thing. Take this set, the 37gr shot the most accurate followed by the 39gr with the 38gr the worst. Did I Ioad the 39grain badly? and the 38grain super badly? I dont see why that would be the case. Interesting thing is the 1943 case v winchester case, 1gr more in the winchester but the velocity is still slower, ergo less internal volume (I should go measure it). The SD gave me an indication of the best group, 37gr 2208 and that was repeated in the 69gr and 77gr, least SD best grouping.

SD (left column),

ADI 2208
28-8-2015
303brit
case 37gr SD
1943 1 2161 2161
2 2182 2182
3 2169 2169
4 2147 2147
5 2082 2082
10741 39.1241613329
2148.2

case
winchester 38gr SD
1 2103 2103
2 2202 2202
3 2082 2082
4 2078 2078
5 2161 2161
6 2097 2097
7 2214 2214
8 2097 2097
9 2163 2163
10 2072 2072
11 2111 2111
12 2112 2112
13 2080 2080
27572 48.030305604
2120.9230769231



1943 39gr SD
1 2220 2220
2 2307 2307
3 2249 2249
4 2385 2385
5 2294 2294
11455 63.0594957163
2291


===============
another set,
===============
case 69gr factory
adi smk 2684 2684
guncity std ammo 2710 2710
good accuracy 2701 2701
2676 2676
2701 2701
13472 13.9391534894
2694.4

69gr tmk 24.0gr
2530 2530
2535 2535
2547 2547
2517 2517
good SD 12.4197423484
10129
2532.25


69gr tmk 24.4gr
2560 2560
2615 2615
2615 2615
2609 2609
2583 2583
12982 24.265201421
2596.4

69gr tmk 24.8gr SD
adi case 2612 2612
2208 2598 2598
2572 2572
2591 2591
16.6408132814
10373
2593.25
=============

So I am taking I need to add 150fps to approach the standard factory ADI load and its accuracy of < 1MOA, so I need some BM2.

I will have a look at the ES next.

These are Fed205MAR primers for the 69grain and Fed210 for the 303brit. I have some 210M I will try these to see if they improve the SD at all.

I would also say the wincester cases are more consistant for weight then the 1943 cases.

What would be interesting is whether SD can give you an indication of a wearing barrel. The stag barrel is brand new while the Pattern 1914 is 100 years old. yet more things to experiment with.