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Reducing ES & SD

Posted: Wed Oct 26, 2016 9:09 pm
by Barossa_222
With all this talk about barrel tuning and load tuning for long range shooting, what is required to reduce ES & SD to acceptable levels. I feel like I have a fairly good loading technique, just wondering if I may be over looking something. I currently have an SD of 6.6 and an ES of 23 over 20 shots measured over my magneto speed . The calibre is a 308 using 200 hybrids and 2208. Educate me please.

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 7:12 am
by Barry Davies
Match your case ( volume ) with powder load - not too much air gap.
Sort primers ( by weight )
Consistent neck tension and not too much of it -- 1 to 1.5 thou is heaps
For starters.

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 8:48 am
by jasmay
A high quality set of scales also helps, Lab scales not your bog standard RCBS stuff...

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 12:24 pm
by Barossa_222
I'm already using lab scales. Does weight sorting primers make that much difference?? How much variation do you find with them?

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 1:01 pm
by DenisA
Barossa_222 wrote:I'm already using lab scales. Does weight sorting primers make that much difference?? How much variation do you find with them?


There's a recent ozfclass thread on weight sorting primers viewtopic.php?f=5&t=7895

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 1:08 pm
by shooter mcreid
Maybe some bullet sorting

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 3:35 pm
by Brad Y
Case sorting and prep and testing different primers and beaches of primers. Sorting by seating tension has helped me as well.

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 3:50 pm
by ajvanwyk
Brad Y wrote:Case sorting and prep and testing different primers and beaches of primers. Sorting by seating tension has helped me as well.


Brad, Out of interest, how do you go about sorting seating tension ?

Albert

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 5:08 pm
by johnk
Best thing that happened to me was when the arthritis in my right thumb got so bad I couldn't feel primers seating for the screaming, so I bought myself a K & M Primer seater with gauge (http://kmshooting.com/primer-tools/prim ... gauge.html). It's slower than the second coming to use but it does a couple of useful things for me:

    I can sort primers by top of cup to bottom of anvil feet. What turned out to be amazing was just how the PMC Russian LR primers were in that dimension - there wasn't more than a thou variation in any batch - unlike about every other brand I've sampled.
    I am able to seat the primers with exactly the same unit of crush (measured in thousandths of an inch) case to case.

Thus I can tighten both my ES & SD

All this can occur because the device is able to measure the depth of the primer relative to that of the primer pocket of the case being used (not the rim of the case like some other brands), which thus allows me amazing precision in seating crush - and permits me to use both thumbs on the lever without much pain.

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 6:39 pm
by Julian D
Maybe a good quality annealer :D

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 7:16 pm
by macguru
I talk to alot of f-open shooters and generally hear the same things. It would be good to get some of the heavy benchrest people's input as well ...

personally , my load tuning is a bit hit and miss, so quite wasteful, I tend to seat 5 thou off the lands and try various powder charges. eventually i get there :)

the biggest improvement lately has been reducing neck tension to only 1 thou. The bullets are still firmly seated which is good because i cant afford an annealer.

Re: Reducing ES & SD

Posted: Thu Oct 27, 2016 8:11 pm
by Barossa_222
I have a very good locally made annealer. Can someone explain how the crush tolerance on primer seating reduces these figures?