6 SLR ES/SD help

[montana_native]

Primers did not help. The magnum primers bumped velocity but ES was about the same as it was with the CCI200s. I tried GM215Ms, CCI250s and GM210s. Accuracy was worse with all of them. These were all 5-shot groups.

I may try a seating depth test to see if that helps settle things down. I've had success in the past with that mellowing out SD.

I also tried Retumbo powder. It's obviously too slow for this application.

 

[savagedasher]

Primers did not help. The magnum primers bumped velocity but ES was about the same as it was with the CCI200s. I tried GM215Ms, CCI250s and GM210s. Accuracy was worse with all of them. These were all 5-shot groups.

I may try a seating depth test to see if that helps settle things down. I've had success in the past with that mellowing out SD.

I also tried Retumbo powder. It's obviously too slow for this application.

Have you checked the internet volume of the cases ? Till that is the same You can expect hi ES . Larry

 

[XTR]

Have you checked the internet volume of the cases ? Till that is the same You can expect hi ES . Larry

I don't believe internal volume is going to make 70FPS difference. I keep something close to 1000 308 cases in rotation for my F-TR loading, and I can assure you I don't check volume or weight sort cases. My ES is under 15FPS for 10 shots and more often than not doing 5 shot tests it's under 10 with my magneto speed.

One thing for the OP, make sure your bayo on your magnetospeed isn't slipping. That one causes pretty big discrepancies.

 

[savagedasher]

I don't believe internal volume is going to make 70FPS difference. I keep something close to 1000 308 cases in rotation for my F-TR loading, and I can assure you I don't check volume or weight sort cases. My ES is under 15FPS for 10 shots and more often than not doing 5 shot tests it's under 10 with my magneto speed.

One thing for the OP, make sure your bayo on your magnetospeed isn't slipping. That one causes pretty big discrepancies.

Mine is under 5 but only with cases with the same amount of capacity . Larry

 

[Auto-X Fil]

I have never sorted brass, and SDs are always in the single digits. I use Lake City, Hornady, Winchester, and Lapua brass, in many calibers from .223 to 300 WSM.

 

[jlow]

I don't believe internal volume is going to make 70FPS difference. I keep something close to 1000 308 cases in rotation for my F-TR loading, and I can assure you I don't check volume or weight sort cases. My ES is under 15FPS for 10 shots and more often than not doing 5 shot tests it's under 10 with my magneto speed.

One thing for the OP, make sure your bayo on your magnetospeed isn't slipping. That one causes pretty big discrepancies.

I would agree with that if I was using Lapua but Winchester well.... Let's just say I've seen some pretty extreme spread in case weight.

 

[montana_native]

This is what I came up with for case weights. This is the first time I've done it so any and all advice and feedback is welcome. Thanks.

Weights are in grams.

 

[jlow]

This is what I came up with for case weights. This is the first time I've done it so any and all advice and feedback is welcome. Thanks.

Not sure what weight units those are - we normally use grains and I was expecting something like 170ish grains?

 

[montana_native]

Not sure what weight units those are - we normally use grains and I was expecting something like 170ish grains?

I just edited the post. Weights are in grams. Thanks for the catch.

 

[jlow]

So as far as I can tell, weight range is 10.08 grams (155.6 grains) to 10.30 grams (160.0 grains) about a 4.4 grains spread so not terrible.

 

[montana_native]

So as far as I can tell, weight range is 10.08 grams (155.6 grains) to 10.30 grams (160.0 grains) about a 4.4 grains spread so not terrible.

OK. Thanks for the reply. I wasn't sure if these weights represented an issue or not.

Thanks again.

 

[bsumoba]

I have seen faster powders result in better ES/SD. Maybe try a faster powder like H4831SC?

If you are outside accuracy nodes, ES/SD are typically higher and as you approach accuracy nodes, they tend to tighten up. Have you done a proper load workup?