Reducing ES

[WahooYahoo]

Yes, I did choose two loads from my ladder based on velocities. The original ladder was at 0.2gr increments. For example;
43.2 2595
43.4 2590
43.6 2599
43.8 2646

So I chose 43.5 as one area to test since this was in the middle of an area that had small velocity changes with increasing charges. I was surprised to see a larger ES for 5 shots with all the same charge. The fact that I got a larger ES in 5 of the same charge than those with incremental increases is what made me think that something else is going on here. I assume I'm doing something wrong.

I question your data. Try a different chronograph. You may be chasing a ghost.

 

[John Klingenberg]

Crimp the cartridge. Good quality brass helps immensely. I've had some fantastic accuracy with R15 but that stuff is incredibly sensitive to temps in my experience. If you load a cartridge off the bench and then one out of your pocket you've messed up.

 

[Buckreed]

Crimp the cartridge. Good quality brass helps immensely. I've had some fantastic accuracy with R15 but that stuff is incredibly sensitive to temps in my experience. If you load a cartridge off the bench and then one out of your pocket you've messed up.

I was keeping them in my pocket until I shot them but I messed up and shot them in succession without waiting. I have lapua brass coming now so when I get that I will make sure I wait between shots and keep them all out in the same conditions.

 

[Buckreed]

I question your data. Try a different chronograph. You may be chasing a ghost.

Interesting, I have a old school light beam chrono. I could use the magneto speed on the barrel and shoot through the light beam chrono. That would tell me if they are different but I suppose I won't know which is correct. For my benefit, what makes you question the data?

 

[Buckreed]

I anneal for every loading. I condition the primer pocket and deburr the inside of the flash hole the first time I prep the brass, then don't touch them. Chamfer the case mouths with a VLD deburring tool.

BUT I found that different neck tension will drastically change ES. So now I use the Redding Imperial Dry Neck Lube instead of the Mica lube. I use a wire brush on my case prep center to remove carbon, then use that lube. ES readings dropped, last time I checked I shot 5 rounds, velocity varied from 3219 to 3226 fps. In previous testing I have seen a 50+ fps increase just due to tight necks when seating the bullets.

Biggest change in ES was seen by switching from Mica to the Imperial Dry Neck Lube. I tumble my brass in untreated corn cob media after sizing the brass too.

Thanks. I few guys have mentioned this now. I will try this process when my new brass shows up

 

[jedimonkey]

Make sure powder is within .01 of a grain--------------

 

[JBarton]

The 2 things I have done to get my numbers down are annealing and using a mandrel die to size my necks. I also now wet tumble after annealing so I guess 3 things. Im sure if I started using the dry neck lube it would probably help a little as well. Once I got below 20 I noticed that I was not seeing as noticeable reductions or gains. But when you are consistent with your process and make sure everything is as exact as possible you find that your numbers really don't move much and accuracy is improved. Using a temp stable powder helps as well. I try to stick with the Hodgdon extreme powders if I can.

 

[BillLarson]

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!

How close do you measure powder....???.
To get single digit SD.and low ES numbers i believe you have to weigh powder to +/- .02 gr.this requires a good scientific scale.
Bill

 

[Tommyrexx]

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!

Just from a quick scan, I'd say the brass should be high quality like Lapa, Peterson or Alpha. You can still sort by weight. Also, a bushing die may help. I've gotten much more consistent loads since going to high quality brass.

 

[Buckreed]

Make sure powder is within .01 of a grain------------

How close do you measure powder....???.
To get single digit SD.and low ES numbers i believe you have to weigh powder to +/- .02 gr.this requires a good scientific scale.
Bill

my scale is a rcbs beam scale. 0.1 settings and eyeballing the line. I do have new brass coming now but I will consider a better scale. Thanks for the help.

 

[capona]

Once you start looking at accurate scales to .01, your in for $$$$

 

[Buckreed]

Once you start looking at accurate scales to .01, your in for $$$$

I assume so. I'm looking for a compromise. Lots of good suggestions from everyone here. I'm not competing or LE so I need to do what I can with a modest budget.

 

[BillLarson]

Once you start looking at accurate scales to .01, your in for $$$$

You can get an A&D FX-120i for around 700$ maybe less...
They are worth it if you wanna shoot out past 500yds.

 

[capona]

You can get an A&D FX-120i for around 700$ maybe less...
They are worth it if you wanna shoot out past 500yds.

I paid $399 used for mine. And I agree it's been worth every penny even if I had paid $700 for anew one. It's on the money every time and quick. But it does cost some $ for a good electronic scale and most of us buy a cheaper version until we realize it's been a waste of money.

Buy once, cry once as they say.