Standard Deviation & Extreme Spread - What does it take?

[cycloneshooter]

I am an avid shooter and "frustrated" reloader. I have played the highpower shooting game for many years and am ranked master long range. However, match shooting and game shooting is a whole different ballgame. I can shoot really good tiny groups at short to mid range, and have even taken game at long range, but the numbers my reloads produce just aren't there to be super confident. Looking for some help & advice. I am wondering what it takes to produce better reloads...

Some background, I am using Redding FL dies for the most part. No bushings, standard expander balls, and I set my dies for minimal shoulder bump. Clean, deburr flash holes. Weight sort brass of high quality like Lapua, Nosler etc. and Winchester on the low end. Using high quality long range bullets like ELD-X, Accubond LR, Ballistic Tips etc. I use a RCBS chargemaster powder dispenser. Generally use Hodgdon, Reloader or IMR powders in that order. I try and variety of primers.

Have borrowed a few screen type chronographs in the past, but they are generally frustrating to set up and get shots to record regularly. Just purchased a MagnetoSpeed Sporter chronograph this spring and it is really nice. Simple to use and records every shot. That said, I figured the chronograph might have been part of my historical problems, but my new SD and ES numbers are the same as always....

A quick example. Built a 280 Ackley last year. Had it out early this summer, 85°F and humid, 60gr H4831SC, 150gr AccubondLR, .010" jump. 2966fps avg, SD 15, ES 45 over 8 shots. Had the same gun out Saturday. 74°F and nice. Same chronograph, same charge, same bullet, .070" jump. 2997fps avg, SD 21 ES 67 over 9 shots. Groups were in the 0.4-0.6 MOA range. These are not the kind of SD and ES numbers that convey confidence at "long range"...

And then...I shot a T/C Encore 257R. Same reloading methods and equipment. And all the sudden the SD is 5 and ES is 18!!! Best I have ever gotten! By a long margin! Thats the kind of numbers i would like to see all the time!

So my question is...what the heck does it take to consistently produce low SD/ES reloads?

I have considered switching to bushing dies and neck turning to better control neck tension than the standard expander buttons. Is that the magic missing link?

Any help, advice, scolding is needed and appreciated.

Frustrated in Iowa...

 

[Barrelnut]

I do think neck tension is the missing link. IMO bushing dies and neck turning help a bit more with over working brass and run-out though. Before trying those, I would try annealing case necks and make sure that all of the brass is sorted by weight and the number of times fired. Brass that is fired once or twice will have a different amount of neck tension than brass that has been fired 3 or 4 times.

 

[FearNoWind]

Did you expect a .060 change in bullet seating to produce the same results?

 

[Kmccord]

Tagging in

 

[cycloneshooter]

Did you expect a .060 change in bullet seating to produce the same results?

No, absolutely not. My point being that nothing I do seems to makes an improvement in numbers, only group size. I was blown away when my TC 257Roberts all the sudden showed SD5/ES18 numbers. Nothing in my process has changed recently, and I am always above 40 ES with everything else.

Maybe I need to be asking, what ES numbers do folks feel are acceptable for making/taking long range shots?

 

[cycloneshooter]

I do think neck tension is the missing link. IMO bushing dies and neck turning help a bit more with over working brass and run-out though. Before trying those, I would try annealing case necks and make sure that all of the brass is sorted by weight and the number of times fired. Brass that is fired once or twice will have a different amount of neck tension than brass that has been fired 3 or 4 times.

I certainly agree with your comments with shooting brass from the same 'vintage'. I do that with all of my long range loads, even used to do that with the 600 yards loads in highpower competition with the AR-15 and LC brass.

 

[Ckleeves]

It might be worth double checking your powder weights on another scale after they come off the Chargemaster. I have seen them do funny things more then once.

 

[6fatrat]

For my 1000yd prone rifles I use brass [Lapua] from the same lot, weight sort, neck turn, anneal then fireform. I anneal after each firing. I use a bushing die sizing my necks for .001 to .002 tension, I also moly all my long range bullets. Get a good electronic scale and use the Hodgon extreme powders. Test different lots and manufacture of primers. Extreme spreads should be under 10. I would start at .010 jump then move into the rifling from there.
Steve Bair

 

[Greyfox]

I generally can achieve ES better then 15 FPS or under 10 SD with my rifles....no magic.
I never had much luck getting tight ES with the standard Redding or RCBS FL or NS dyes used with an expander plug. Neck tension tends to be high and brass is often overworked. I use Redding bushing dyes choosing a bushing that results in neck tension under 002" for a light and very consistent seating pressure. Run outs also tend to be better. . Wnenever oossible I prefer the very consistent Lapua and Norma brass,

 

[FearNoWind]

Maybe I need to be asking, what ES numbers do folks feel are acceptable for making/taking long range shots?

My own standard is < 12
Nevertheless, I don't put much stock in the ES/SD figures. I let the target tell me what works. If it's good at 100 I take it out to 300. If it's good at 300 I take it out to 500. If it's good at 500 it ain't broke and I don't try to fix it - regardless of what the ES/SD figures might be.

 

[bob4]

Nevertheless, I don't put much stock in the ES/SD figures. I let the target tell me what works. If it's good at 100 I take it out to 300. If it's good at 300 I take it out to 500. If it's good at 500 it ain't broke and I don't try to fix it

Agreed. If you're shooting .4-.6 @100 take it out further. I bought a magneto speed a few yrs back. I was trying to get numbers down for a while and stopped paying attention to the paper. I'm a ragged hole at 100 and well under about 1.6 at 300 now. I should break out the chrono just to see.

 

[Kmccord]

It might be worth double checking your powder weights on another scale after they come off the Chargemaster. I have seen them do funny things more then once.

I have an RCBS charge master that I bought in 2000, I always calibrate the scale and dispenser before starting on a reloading session. I was having extreme spreads on my loads and decided to pull out the old balance beam scale and verify if the electronic scale was measuring the same as the balance beam, what I found to work for me, is every charge that is thrown in the charge master is verified with the balance beam and it verified what I was thinking, the electronic would change during the session from a half grain to almost a full grain at times. This did eliminate my 40+ ES down to the teens to lower 20s. This adds more work, but I am not in a hurry during my loading, it did help, but I am not down into the single digits like I have seen some claim.

 

[Lonewolf74]

I have experienced better ES and SD in a couple loads by nothing more than crimping with a Lee collet die. This leads me to believe that consistent neck tension is a bigger factor in achieving good ES and SD so pursuing this is also my next venture.
Not meaning to hijack but a question I have is how do you figure out what bushing will get you to .002 neck tension? Or in my case I have Forster FL dies that I want to have the necks honed, how do I figure out how much should be honed out?

 

[jimbires]

I have experienced better ES and SD in a couple loads by nothing more than crimping with a Lee collet die. This leads me to believe that consistent neck tension is a bigger factor in achieving good ES and SD so pursuing this is also my next venture.
Not meaning to hijack but a question I have is how do you figure out what bushing will get you to .002 neck tension? Or in my case I have Forster FL dies that I want to have the necks honed, how do I figure out how much should be honed out?

measure the neck diameter on a loaded round , and subtract .002" off that number . this gives .002" neck tension .