Load work up question

[Danny1788]

When working up loads for LR shooting do you take the best group or the group with the lowest ES an SD? My smallest group wasn't my lowest ES. But my load with the least ES wasn't bad I think 3/4moa at 100. Do you start with the lowest ES group and fine tune with seating depth changes? Or go the other way and take your best group and fine too seating depth to help ES? Thanks

 

[rscott5028]

ES has limitted value. SD is a much better measure of consistency.

Also, you haven't said anything about the number of samples. The more you have, the higher confidence you can have going forward.

I would try the load with the smallest groups and the load with the smallest SD/ES several more times to see if either one is consistent and repeatable.

-- richard

 

[Joe King]

ES has limitted value. SD is a much better measure of consistency.

Also, you haven't said anything about the number of samples. The more you have, the higher confidence you can have going forward.

I would try the load with the smallest groups and the load with the smallest SD/ES several more times to see if either one is consistent and repeatable.

-- richard

that ^ and move it out to 200, you might find some interesting results going farther out

 

[Danny1788]

Thanks for the advice I guess I should have thrown out more info. It's a custom built .338 edge just finished doing barrel break in with 300gr Berger OTM and H1000. 93gr gave me an Es of 6 and 2803 fps average. I need to shoot it at 300yds to do a true test of accuracy. Thanks for the advice though.

 

[Mikecr]

I think the table will turn with distance.
And I think you'll likely need to start over with some of you load development.

 

[RockZ]

Cal,
Loks like you found a great powder charge with a low e/s Now to fine tune it do a seating depth test until you find a depth that will put the bullets in the same hole at 100yds.
I initially do two shots at each seating depth until I find one that puts two bullets in nearly the exact same hole, not just touching. when i find the best seating depth then I shoot them at 600yds and see what I get. I always get the e/s down and at 6fps it looks great for you and you shouldn't get much vertical at long range.
Here's a link to a group I shot with my 338 Lapua AI.
http://www.longrangehunting.com/forums/f19/265gr-hat-group-52192/

 

[Danny1788]

Mikecr how will shooting at a distance change my ES? The ES of 6 is great and pretty sure most people would say with a 28" barrel and a 300gr Berger with 93.0gr of H1000 at 2803fps it's a safe load. I'm just a little confused by your comment I think I will stick with this load and do some seating depth testing to perfect the load. Now I know that changing the seating depth can change the ES but how much?

 

[rscott5028]

I think he meant that the one with the most consistent velocity will group best at long range.

-- richard