Reducing ES

[Buckreed]

Here is my question to everyone. How do you reduce your ES?
I shot a ladder of 15 rounds (incremental at 0.2 gr. each) over my magneto speed, plotted the results, and found two flat spots of velocity.
43.5 and 44.5 were both in the middle of the flat areas.
I loaded 5 at 43.5 and 5 at 44.5. All ten were loaded exactly the same as the rounds in the ladder.
On the 5 of 43.5 I got an ES of 78
On the 5 of the 44.5 I got an ES of 51

Obviously I would like this to be closer to 10. What do you suggest? Different brass? Neck Tension issue?
Here are the components I'm using.
RL 15
Winchester Brass
Berger 175gr VLD
Federal #210 primers
0.015 jump

Thanks for the help!

 

[JMW67]

neck tension like you stated or try a different primer make sure your brass is sorted and prepped

 

[Buckreed]

Thanks. I'll try sorting my brass first and see what that does.

 

[Rick Richard]

If load produces less than half inch groups, I have had good luck lowering ES and SD by sorting brass by weight. Just my experience.

 

[Slick8]

Get your hands on some adg or lapua brass if made in your chamber.

If not, weight sort and trim. Neck tension would be next.

 

[Buckreed]

Thanks guys. I'm weighing them up now. Need to buy a digital scale. Lol. This a pain with a beam scale.

 

[JMW67]

weight does not tell you everything volume tells it all I have taken brass with a fairly large weight spread checked water volume and they were very close

 

[Rick Richard]

weight does not tell you everything volume tells it all I have taken brass with a fairly large weight spread checked water volume and they were very close

Agree, however I use Lapua brass which minimizes the concern regarding weight variances...very consistent as compared to others in my experience

 

[L.Sherm]

That E.S is enormous, I would switch powders. Win brass isn't bad after its sorted and prepped.
When you start getting the E.S down in the neighborhood of 20 then start paying attention to your targets.

 

[Justice1327]

If you have them , primer change is a quick way to see if a difference can be reached. Otherwise, Set your neck tension using mandrels. This is easy to do and is faster than weight sorting. Next I would trim the necks because after the mandrel pushes out the neck all the inconsistencies are there for you to trim off.Depending on the purpose of the cartridge you will only need .001 neck tension for target shooting but can use 2 to 3 For other purposes.
However there is something else to consider.

 

[JMW67]

you are right on the money top tier brass is the only way to go takes out alot of work and wondering what the hell is happening lapua, peterson adg, alpha are my top choices

 

[Buckreed]

Ok, so my logic maybe flawed here but it grabbed the last five I shot with the ES of 51. Here is what I found.
1630
164.0
165.0
165.7
165.2
SD of 0.87 does that seem reasonable? I can check volume next too. Good comment from JMW67 just haven't got that far yet.
I'm thinking if I can show that the brass was not an issue (on these 5) maybe I move on to neck tension. Obviously sorting would be in my prep process going forward as well.
What do you think?

 

[Justice1327]

You could also mess with seating depth that does help your accuracy and also can impact ES/SD. Lastly,Depending on the powder and how quickly it burns , I feel that sometimes it can disrupt the neck tension on the bullet when it is set to loose. Causing the bullet to start its path down the barrel prior to the powder pressure reaching its potential or in a more gaseous state. So Based on the weight of the bullet and the powder charge are you shooting at 308 and or a 708?

 

[JMW67]

how many firings on the brass