Trouble shooting high ES

[lrgoodger]

To echo slightly on what larry was talking about , i conducted a test on a set of brass that was wieght sorted.

I had grouped lots of brass that were withing .3 of each other as wieghed on an A&D Fx120i as well as the powder charges were kept within .01.

What i then did was run those batches over the chronograph and wrote in felt marker the velocity of each shot on that particular case..

Then I sorted the brass based on the written velocities.. Bingo , dropped the es down into the single digits as compared to what they were when they were merley wieght sorted ( es's were previously 20-28fps)

The first thing i noticed was there were quite a few cases that were within the same wieght catagory but had to be segregated into a completely different lot once compared to the velocities written on them.

Those same cases after bieng sorted by speed have since stayed in their corresponding lots as they seem to be consistent in their velocities still.

Good luck.

This sounds like a good idea but won't conditions from day to day prevent you from accurately sorting brass by MV? In other words, can cases shot on one day with a specific MV range be grouped with cases having the same MV range from another day?

Why would conditions (atmospheric) affect the bullet by the time it reaches the muzzle? Atmosphere only affects bullets after they leave the muzzle. It is doubtful the short distance between the muzzle and the chrono would matter much. There are other variables that detract from the accuracy of this method, but it is better than doing nothing about the case volume issue.

 

[rminut]

I would have to set down and calculate my SD for the H4831 load. I've tested it twice and the ES was 36 & 41. The SD for the H1000 load was 20 and ES 61. Yes I've been using the same lot of brass. The score was shot at 600y. This all started as a quest to find more speed. The H1000 shot well enough in testing that I want to use it in the upcoming match at club. It shots well enough for banging steel in which it was built for. However, if I want to be competive in our monthly Fclass I think I need to do better.

At 600y what is considered acceptable accuracy? Maybe I'm getting worked up for nothing.

Scott

If ES is high with both powders then I would look to neck tension, as others have mentioned. The numbers I see people trying to get are single digit SD and no more than 20 for ES for 1k shooting. looking for more speed while shooting at 600 is pennywise and pound foolish, it just won't make a big difference points wise. 1000 is where those small gains matter. go for accuracy, but good shooting trumps everything done at the reloading bench. perfecting your shooting techniques is what will really show on the target.

 

[MOShooter]

I think that my neck tension is where the brass is really affecting me. I can feel that some seat harder than others and it affects my OAL. This rifle was built for PRS matches. My MV is only about 2900 and it looks like most of the guys are running about 3100 so I'm giving up a lot in that game.

Scott

 

[tuttlefarm]

Just turn your necks and stop second guessing. Just turning necks should put your es at 25-30. KISS............

 

[bill123]

To echo slightly on what larry was talking about , i conducted a test on a set of brass that was wieght sorted.

I had grouped lots of brass that were withing .3 of each other as wieghed on an A&D Fx120i as well as the powder charges were kept within .01.

What i then did was run those batches over the chronograph and wrote in felt marker the velocity of each shot on that particular case..

Then I sorted the brass based on the written velocities.. Bingo , dropped the es down into the single digits as compared to what they were when they were merley wieght sorted ( es's were previously 20-28fps)

The first thing i noticed was there were quite a few cases that were within the same wieght catagory but had to be segregated into a completely different lot once compared to the velocities written on them.

Those same cases after bieng sorted by speed have since stayed in their corresponding lots as they seem to be consistent in their velocities still.

Good luck.

This sounds like a good idea but won't conditions from day to day prevent you from accurately sorting brass by MV? In other words, can cases shot on one day with a specific MV range be grouped with cases having the same MV range from another day?

Why would conditions (atmospheric) affect the bullet by the time it reaches the muzzle? Atmosphere only affects bullets after they leave the muzzle. It is doubtful the short distance between the muzzle and the chrono would matter much. There are other variables that detract from the accuracy of this method, but it is better than doing nothing about the case volume issue.

I notice fluctuations in MV between shooting sessions and lacking another explanation, attribute it to different temperatures. If you are aiming for single digit ES then I would think that you would either have to have real consistency from day to day or settle for culling the cases that account for extreme MVs each time you shoot.

 

[Patch700]

To echo slightly on what larry was talking about , i conducted a test on a set of brass that was wieght sorted.

I had grouped lots of brass that were withing .3 of each other as wieghed on an A&D Fx120i as well as the powder charges were kept within .01.

What i then did was run those batches over the chronograph and wrote in felt marker the velocity of each shot on that particular case..

Then I sorted the brass based on the written velocities.. Bingo , dropped the es down into the single digits as compared to what they were when they were merley wieght sorted ( es's were previously 20-28fps)

The first thing i noticed was there were quite a few cases that were within the same wieght catagory but had to be segregated into a completely different lot once compared to the velocities written on them.

Those same cases after bieng sorted by speed have since stayed in their corresponding lots as they seem to be consistent in their velocities still.

Good luck.

This sounds like a good idea but won't conditions from day to day prevent you from accurately sorting brass by MV? In other words, can cases shot on one day with a specific MV range be grouped with cases having the same MV range from another day?

Why would conditions (atmospheric) affect the bullet by the time it reaches the muzzle? Atmosphere only affects bullets after they leave the muzzle. It is doubtful the short distance between the muzzle and the chrono would matter much. There are other variables that detract from the accuracy of this method, but it is better than doing nothing about the case volume issue.

I notice fluctuations in MV between shooting sessions and lacking another explanation, attribute it to different temperatures. If you are aiming for single digit ES then I would think that you would either have to have real consistency from day to day or settle for culling the cases that account for extreme MVs each time you shoot.

That is correct Bill , if you tested and batched a lot of brass on monday and got the results you were looking for(with respect to a low es) and then shot those batches on saturday with a different condition then yes you will see a velocity change however the change will be the same with all the cases ... The es will still be low.

 

[bill123]

To echo slightly on what larry was talking about , i conducted a test on a set of brass that was wieght sorted.

I had grouped lots of brass that were withing .3 of each other as wieghed on an A&D Fx120i as well as the powder charges were kept within .01.

What i then did was run those batches over the chronograph and wrote in felt marker the velocity of each shot on that particular case..

Then I sorted the brass based on the written velocities.. Bingo , dropped the es down into the single digits as compared to what they were when they were merley wieght sorted ( es's were previously 20-28fps)

The first thing i noticed was there were quite a few cases that were within the same wieght catagory but had to be segregated into a completely different lot once compared to the velocities written on them.

Those same cases after bieng sorted by speed have since stayed in their corresponding lots as they seem to be consistent in their velocities still.

Good luck.

This sounds like a good idea but won't conditions from day to day prevent you from accurately sorting brass by MV? In other words, can cases shot on one day with a specific MV range be grouped with cases having the same MV range from another day?

Why would conditions (atmospheric) affect the bullet by the time it reaches the muzzle? Atmosphere only affects bullets after they leave the muzzle. It is doubtful the short distance between the muzzle and the chrono would matter much. There are other variables that detract from the accuracy of this method, but it is better than doing nothing about the case volume issue.

I notice fluctuations in MV between shooting sessions and lacking another explanation, attribute it to different temperatures. If you are aiming for single digit ES then I would think that you would either have to have real consistency from day to day or settle for culling the cases that account for extreme MVs each time you shoot.

That is correct Bill , if you tested and batched a lot of brass on monday and got the results you were looking for(with respect to a low es) and then shot those batches on saturday with a different condition then yes you will see a velocity change however the change will be the same with all the cases ... The es will still be low.

I assume then that there is no way to reliably sort a large amount of brass shot on different days using MV?

 

[lrgoodger]

That is correct. All the brass you are sorting by MV would have to be shot at the same ambient temperature.

I was going to keep this quiet until it was ready, but I am working on a loading bench tool for precision shooters that will quickly and reliably sort brass by internal volume. It is long overdue.

 

[bill123]

That is correct. All the brass you are sorting by MV would have to be shot at the same ambient temperature.

I was going to keep this quiet until it was ready, but I am working on a loading bench tool for precision shooters that will quickly and reliably sort brass by internal volume. It is long overdue.
[/quoteI
Is temp the only factor? It would be reasonable to shoot different batches on different days, tracking temp.

Looking forward to seeing the tool you are working on.

 

[savagedasher]

Neck tension does not change ES as much I you are jumping .020or more. When load you always add 2000 PSI or more to initial start pressure when near or in the lands. .020 more off a soft touch always gives better ES. Larry

 

[amlevin]

Case prep is paramount in lowering ES but don't overlook the relationship of powder and case fill. Some powders just don't like to be lonely in the case. If you aren't filling the case up close to the shoulder, and have High ES, then consider a powder that fills the case more at the necessary charge weight.

Seating depth changes can not only provide more or less jump, they can also alter the case volume to powder charge relationship, yielding more consistent performance.

 

[savagedasher]

Case prep is paramount in lowering ES but don't overlook the relationship of powder and case fill. Some powders just don't like to be lonely in the case. If you aren't filling the case up close to the shoulder, and have High ES, then consider a powder that fills the case more at the necessary charge weight.

Seating depth changes can not only provide more or less jump, they can also alter the case volume to powder charge relationship, yielding more consistent performance.

Brand and type of powder fits in also. My reloading room is 65 degrees at the range it was 93 in the shade. 30 degree in powder change is a lot in some powders. After 10 or more shots the chamber temp is 130+. Any time the case is in the chamber un fired changes the burn. Where someone is shooting has a big effect on ES. In the winter where the tem average is 70 my ES is better then the 90 plus we have all summer. Powder choice case prep Makes the difference. Larry

 

[MOShooter]

Loaded up 20 rounds tonight using my new scale. The ole chargemaster was doing better than expected. I was running up to 46.2 with it and trickling the rest. All but 1 where within -.04gr and the 1 odd ball was -.08gr. So I think it is safe to say my problem lies somewhere else. After a discussion about primer seating with Alex the other day I paid more attention to my priming. I did notice I wasn't seating some as deep as others. So I made extra sure I was seating them firmly against the bottom of the pocket. Will be interesting to see if these 2 changes show any improvement. Also it will be interesting to use my magnetospeed on my fathers 308 over the holiday. I load it with the same tools using lapua brass.

Scott

 

[dbramley]

How are you cleaning your cases? I found that if I stainless steel too long it rolls the lip of the necks such that even after I chamfer the necks there is still a lip there that causes inconsistent seating.

Dan

 

[BenPerfected]

I ordered a better scale. Going to start there and see if it makes much difference. I still think better brass would make a big difference.

Scott

My experience contradicts your presumption. I've gone from Federal to Lapua to LC and in each case when in a head to head comparison (same velocity, different charge) I could not see the difference over 3 5-shot sgroups, but YMMV. I partially agree with:

LRGoodger
A better scale will only improve the situation, but the percentage of improvement may be so small as to be unnoticeable. Other factors constitute a much larger percentage of the ES issue.

As Erik Cortina once told me, the Holy Trinity of accuracy are 1) Powder 2) Neck Tension 3)Seating depth. I would look there first. A better scale will help with the powder aspect but you've got the other two to consider.

Kindest regards,

Joe

Joe,
What would you say is the Holy Trinity for low ES?
Ben