Standard Deviation & Extreme Spread - What does it take?

[Jerry M]

Tag

 

[couesaddict]

I have a Lyman 1200 and have learned to double check my loads with a beam scale. Biggest thing seems to be static from the powder flowing through it. It went crazy once and the readout would change by more than a grain when I got my hand close to the pan. I called Lyman and they told me to empty the powder and clean it with windex to kill the static. Cleared it right up but I decided never to trust it and have definitely seen its lack of accuracy with my beam scale. Sorry for the long winded post but I thought I'd share. My newest rifle is showing single digit es regularly so the old 5-0-5 beam scale must be pretty accurate

 

[Kansaswoodguy]

How do you clean your brass and what lube you using?

 

[Kansaswoodguy]

Also you said you use a powder throw I do also that is not the issue consistently using one can be however. I load the throw with powder and throw 8 or so charges into a cup dump it back into the hopper and then load all 50 or 100 cases never bumping the table I don't even keep the cases on the same table as the powder throw. I want the same density of powder in every case. I firmly believe the 1 part lanolin to 10 parts 99% isopropyl alcohol spray lube making sure to get inside the necks helps lower SD I also polish my expanders with at least 500 grit. I use walnut tumbler and have heard of guys having issues getting low SD with stainless or sonic cleaning. Are you trimming your cases?

 

[RockyMtnMT]

I like to see my es less than 30fps. Single digit es is not worth chasing (hard). If my es is in the 40's I will switch to a different powder or primer to see if it will clean up. I agree with what others have said about taking the load out farther. If you are shooting .5moa at short range it is certainly worth a few shots at long range. It is tough to shoot well enough to see the difference in 30fps at 1000y.

Good luck

Steve

 

[couesaddict]

I personally gave up the tumbler and sonic cleaner. Impatient I guess. I use braklean or gunscrubber and a rag then a nylon brush in the necks. Super quick and they clean up nice. I used the case lube that came with my rock chucker supreme starter kit for a long time and it worked fine. I've since switched to imperial wax and like it as well. Also I trim and chamfer my brass to get it all to uniform length at .010 under max. Not saying it's all the right way but these steps work for me. Good luck

 

[J E Custom]

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...

It could be anything and you may have to start over.

I used to struggle with load work up and would spend many hours and components before arriving at my goal so I changed the way I loaded and here is "MY" way and it works well for me.

First I start with a powder that gets me 98+ % case capacity at or near
max listed pressure with the bullet weight of choice (Not the biggest or the fastest, but the best weight for what I will be doing with it).
Then based on the powder I choose, I pick an optimum primer for that powder.

After loading 5 rounds of each different selected powders several grains below maximum, to Magazine length I go to the range to chronograph them.

What I am looking for is SDs below 10. I am not looking for groups yet because I am looking for a good powder, primer combination in that case capacity, with the bullet weight preferred.

If I get the desired SD and ES with one load or see a trend that leads me to the best powder primer combination then and only then do I start working on accuracy. I have found that good SD/ES does not automatically mean good accuracy and good accuracy does not automatically mean good SDs and ESs so I work on one at a time. Done be narrow minded about the choice of powders because what works well in some rifles may not work in your rifle. There are powders that I prefer based on many factors, and there are powders that I don't particularly like, but use them because the rifle, barrel, chamber combination does.

Normally If I get good SDs and poor accuracy It is the bullet weight or shape. If I get good groups but poor SDs it is the load (Powder or primer combo) and not the bullet (It tells me that My barrel likes that bullet but not the load.

The reason I load this way is for long range accuracy and have found that if the SD and ESs are not good, the accuracy is inconsistent at longer ranges.

It has also minimized the number of test loads in order to reach an accurate load by working on one thing at a time. I can normally find a really good load with less that 20 shots. After everything is doing well,
I start tweaking the load COAL to see if better accuracy Is possible by shortening or lengthening within the Magazine length. If the load/rifle seem to like load lengths longer than magazine length, I decide then based on use, if I want to single load.

This is just the way I load to solve/find good SDs and accuracy without
a hit or miss approach.

J E CUSTOM

 

[Reloader222]

I have annealed cases for years to try and get neck tension the same (+flash hole deburing etc) and to lower extreme spread, but it really came down dramatically when I started weighing cases in groups. Then I only use those cases within a 1grain variance.

 

[Lonewolf74]

JE, if I understand you right you load up 5 shots at a lower charge weight to check SD. So once this is done and you have chosen a powder do you work up in charge to nail down the load? Do you encounter much where SD opens up as you increase charge weight?

 

[txsendero]

I like this method.

http://www.65guys.com/10-round-load-development-ladder-test/

You already have the Magnetospeed. It recently worked well for my new 6.5WSM. I am now down to fine tuning seating depth.

 

[dmoon]

tag in

 

[J E Custom]

JE, if I understand you right you load up 5 shots at a lower charge weight to check SD. So once this is done and you have chosen a powder do you work up in charge to nail down the load? Do you encounter much where SD opens up as you increase charge weight?

Yes I work up to a near maximum charge and based on the results, I will leave it where it has the best ES and accuracy. Some rifles/barrels like more velocity and some don't, so I look for that node that gives me the best of all, not the best velocity or any one thing.

Most rifles that I have, seem to be just under the max pressure, But a few have only gotten better and I have had to avoid the temptation to keep going up until I start blowing primers or encounter heavy bolt lift.

Normally if you have a good powder, primer and bullet weight combination and case density, SDs will stay the same or improve slightly because the initial ignition start is consistent and adding a few more grains of powder will only increase velocity and pressure. If not the SDs will be all over the place as you change the powder charge.

Getting good SD's and ES's is only the start to getting good consistent, accurate loads in my opinion.

This is just been my experience.

J E CUSTOM

 

[rcoody]

well with a hunting rifle i start with an OCW test at mag length. find my max and that node with 2 or 3 charges with little vertical change. if i have room i will stretch that out to a ladder test. if it is.a.range gun i start with a .010 jam.

then i run a seating depth test. i use .005 increments but berger's seating.depth test works too.

after i find.my seating depth i run another OCW or ladder test with small charge weigh increments

i may even try fine tuning seating.depth after that. suprising what a couple of thousandths can do sometimes.

after all that i pull out the magnetospeed and run 10 or 15 rounds over it. usually i am plesantly suprised. now anneal often, i weigh sort brass, neck turn, weigh powder with Adams Autotrickler to .02 gr, weigh sort bullets and sort by bearing length, i leave the carbon in my necks, use custom sizing dies, seat bullets with wilson inline dies with an arbor press with force gauge and sort by seating pressure and in the end sort loaded rounds by concentricity. now i probably have left some stuff out.

there is a lot of things you can do to lower ES & SD after you find a load. most are listed above. accurate powder charge and consistent neck tension are what i have found to make the most difference.

works for me

 

[cycloneshooter]

Thanks everybody for all the great suggestions and comments! The support is overwhelming!

First question: Is a .002 neck tension appropriate for a hunting rifle?
I have always used standard FL dies with expander balls, so I have never done anything other than 'no crimp'. Will a lighter .001-.002 tension properly hold bullets in place while loaded in the magazine and rifle strapped to a pack? Or when bullets are fed into the chamber?

Now to answer some questions:
I clean my brass in a tumbler, using walnut hulls mainly, but just switched back to corn cob media [lil cleaner]. I do lube my cases prior to sizing and use only Hornady One Shot spray lube with cases standing upright when applying. I do trim brass as needed. Historically have used just the Lee hand trimmers. Just bought a Hornady case trimmer, but haven't used it yet, haven't needed to yet.

I started with a Lee balance beam scale, but upgraded to a RCBS Chargemaster a few years back. It sounds like I need to revisit the balance beam again.

Myself and my shooting buddies like to stick to Hodgdon powders if possible. I have and do use other brands as needed to look for better accuracy and consistency. I have no allegiance in primers, it usually boils down to what i have on hand or can find.

I usually start by running a pressure test, working up to find pressure signs in brass, primer or bolt lift and then back off from there. I like the idea of high side case capacities for uniformity of burning. Find the seating depth node based on accuracy on paper. Starting on the lands or mag length, then backing off in increments of .030-.040" and then fine tuning around whichever major increment shows the best promise.

A few of our latest recipes:
Savage LRH, Nosler Brass, WLRM primer
7mmRemMag, 69.8gr H1000, 162gr ELD-X [.070" jump]. 0.3-0.5MOA
SD15/ES45

03 Springfield Custom, Nosler Brass, WLR primer
280AI, 60gr H4831SC, 150grAccubondLR [0.070" jump] 0.5-0.7MOA
SD21/ES67

Buddies Savage [different chrono, same reloading methods]
300WSM, 62gr H4350, 200gr ELD-X, Norma Brass, TullAmmo primer
SD18/ES57
300WSM, 64gr H4350, 178gr ELD-X, Norma Brass, TullAmmo primer
SD15/ES46

Working on another batch for the weekend.
I tried cleaning necks with a brush. And I did polish the expander ball.