Good ES, groups not so good.

[keen.on.it]

If you were getting ES of 23fps, but groups of 1.3" at 100, would you try anything to get those groups down? Or just move on?
I shot a load development today, and all powder charges had an ES of 23fps or better, but the groups were 1.3" or worse. Sample size for ES was small, so we'd see if that even held, but with a difference of .4gr, the ES of 2 different powder charges was 21fps.
Another load that I worked up, same bullet, different powder, is shooting just over .5", but ES of 68 with about 20 rounds through chrono. I no longer have the brass that I worked up that load with, (nickle plated).
Try getting groups down? or try the other powder with different brass and see what happens?

 

[Rick Richard]

My most recent "moment" was this week when I tried Large rifle primers in place of the Magnum primers in my 7SAUM. ES and SD numbers went to single digits as compared to similar results that you have posted. Thanks to Longtine88 for the recommendation.

 

[Eric H]

I've had simular instances and I took the best group and loaded up numerous rounds of that load. I then went to the range and using the Lee Hand Press pushed them back .01 2 at a time. Tested those two and if grouped well I'd push 2 more back and tested those. I'd do this until I find good groups. Good luck.

 

[Eric H]

I've had simular instances and I took the best group and loaded up numerous rounds of that load. I then went to the range and using the Lee Hand Press pushed them back .01 2 at a time. Tested those two and if grouped well I'd push 2 more back and tested those. I'd do this until I find good groups. Good luck.

In addition, after sizing your brass I highly recommend running them through a mandrel if you're not currently using one. This way they all will have the same tension. I use one that creates a .002 tension.

 

[MagnumManiac]

ES & SD are not what I base my loads on.
Shoot groups, choose the best, then test above/below that in.3g-.5g increments, then do seating depth.
I actually do seating depth and primer tests well before I test powder…

Cheers.

 

[Bang4theBuck]

There are lots of things that can negatively affect accuracy that don't affect velocity and velocity consistency.
*Technique
*Rifle / Bullet compatability
*Something affecting barrel harmonics (not free floated).
*Low quality brass imparting run-out issues.

Need to test known good combinations of bullets, powders, primers to determine what the rifle is capable of in terms of accuracy. There's lots of different approaches to this, but I woukd only settle for mediocre accuracy and good ES, once I was sure it wasn't capable of more by experimenting with different components.

 

[KH_Outdoors]

This sounds like a scenario where your best course of action would be components swapping. Either the bullet or powder, or both. As opposed to more fine tuning, because if you're not starting with mediocre groupings the likelihood of achieving a forgiving tune is almost zero.

This is all assuming of course that you are shooting a good platform to start with, like a quality barrel that was chambered to a quality action. Bedded in a quality stock etc... etc... all while using good hand loading techniques etc... but basically starting with "controlled variables" anyhow.

 

[KH_Outdoors]

My most recent "moment" was this week when I tried Large rifle primers in place of the Magnum primers in my 7SAUM. ES and SD numbers went to single digits as compared to similar results that you have posted. Thanks to Longtine88 for the recommendation.

That @Longtine88 guy knows his SAUM's!

 

[06 SB]

I am no expert but have been loading for decades. I look for low ES and accuracy. If you have a load that has a low ES but not accurate enough, work the issue by changing one variable at a time. I generally switch seating depth, then a different primer, then a different bullet (with the original primer). Usually the first one fixes it.

 

[wasskeet]

I had a 25 Creedmoor that was practically flatlined on ES/SD - would average less than 3 ES across 8-10 shots. A good group with the load @ 100 yds was about .750/.875". Took it to 1000 yds. vertical spread and on one target (only 4 shots on of 5) was less than 1/2" - a half inch, not 1/2 moa. Flat vertical doesn't help anything if you can't keep it horizontally on a 42" target. LOL. So - as others have stated, focus on tight groups, then worry about ES/SD IMHO.

 

[std7mag]

If you were getting ES of 23fps, but groups of 1.3" at 100, would you try anything to get those groups down? Or just move on?
I shot a load development today, and all powder charges had an ES of 23fps or better, but the groups were 1.3" or worse. Sample size for ES was small, so we'd see if that even held, but with a difference of .4gr, the ES of 2 different powder charges was 21fps.
Another load that I worked up, same bullet, different powder, is shooting just over .5", but ES of 68 with about 20 rounds through chrono. I no longer have the brass that I worked up that load with, (nickle plated).
Try getting groups down? or try the other powder with different brass and see what happens?

To me, ES-23 isn't that great.
I'm looking for low teens or single digit.

But the target doesn't lie.

I've seen ES-32 shoot some really good groups.
Just be aware, the further you shoot, the more telling a higher ES/SD is.

 

[BrentM]

Going to be a lot of different methods to get a desired result but ES and SD combined with accuracy is the goal for me. I do start with low sd and es but focus on SD. Part of the reason for low sd vs es is due to brass. In a small sample you could have a weird round that throws your data off. That particular piece of brass might be a cull. So, for me, I shoot the velocity ladder, look for the high node for both low sd and accuracy. It gives me a range to work inside of with a efficient powder charge. From there you can tweak seating depth, tension etc. With lower quality non-prep'd brass I usually change my criteria for desired sd and go from single to teen digits and not worry about it. My 223 trainer is a perfect example. It shoots pretty good but sd and es are wide due to a few pieces. I can feel the tension when pressing in the bullet. That brass 100% needs to be turned at some point.

 

[Rick Richard]

That @Longtine88 guy knows his SAUM's!

You think? I know he does. Lots of fun to be in elk camp with too.

 

[HRM Johnny]

ES & SD are not what I base my loads on.
Shoot groups, choose the best, then test above/below that in.3g-.5g increments, then do seating depth.
I actually do seating depth and primer tests well before I test powder…

Cheers.

Thank you.