SD or ES

[ELR LVR]

Just trying to be funny.
Someone will figure how to take anvils out of primers so they can be measured and weighed, then put back in the cup. How about variation on how much the foil is pressed into the charge. I have some primers where the charge seems to vary a lot. The charge is squeezed above the foil and around the anvil legs. Will look for them and post a pix.

Ive weighed my spent primers
they all weighed exactly the same within .001 Milligram (Cup & Anvil)
So the only weight differences were the charge in the primer
I didnt weigh every brand of spent primer I use
just the ones I weight sort)

 

[jlshaw]

The "single thing" that's the biggest for me as been consistent powder charge measured to +/- .02 grs.

You may have seen this chart before, but I'll show it here as my thinking as to importance of various things for precision shooting is pretty much in line with it:

View attachment 1727508

There's quite a lot of inter-relatedness with these factors. For example, charge weight can chamber pressure, as can primer selection, and so on. Having said that, the chart seems about directionally right.

 

[Bottom Fodder]

Just trying to be funny.
Someone will figure how to take anvils out of primers so they can be measured and weighed, then put back in the cup. How about variation on how much the foil is pressed into the charge. I have some primers where the charge seems to vary a lot. The charge is squeezed above the foil and around the anvil legs. Will look for them and post a pix.

I think some sort by color, your “ funny” maybe just what this thread needs right now

 

[B Nettesheim]

Leaving the chronograph at home and reading the groups at 1k

 

[Mike TackleBerry]

One of the bigger factors that most people overlook is donuts. Most people don't realize they have them, and they'll wreak havoc on your SDs.

 

[Bottom Fodder]

One of the bigger factors that most people overlook is donuts. Most people don't realize they have them, and they'll wreak havoc on your SDs.

I guess that would some what be considered neck tension , would you agree

 

[JEFFPPC]

Overall the single biggest thing I have done is precise powder charges. 1 piece of powder quite often. But with 3 benchrifles with sd numbers from 12 to 17. how do you lower them? I did that with primers both by weight sorting then testing by brand. All 3 rifles went in single digets....1...4...9.

 

[Shooter13]

Overall the single biggest thing I have done is precise powder charges. 1 piece of powder quite often. But with 3 benchrifles with sd numbers from 12 to 17. how do you lower them? I did that with primers both by weight sorting then testing by brand. All 3 rifles went in single digets....1...4...9.

Did your qroups shrink?

 

[ELR LVR]

Leaving the chronograph at home and reading the groups at 1k

I like this,
I didn't use a Chrono for years,
Shot my last one and said meh
and load developed like that according strictly to the target
and the loads repeatability
If I develop a load in June and need 1.7 Mils for 600
then go back out in Nov and need 1.7 Mils for 600 and make 1st round hits
I dont care what the Chrono says
nor care how fast the load was going, but was only concerned with accuracy
---
I got a chrono again now but
Honestly like load development without it, I dont chase speed anymore

 

[Mike TackleBerry]

I guess that would some what be considered neck tension , would you agree

While it is physically part of the neck area, it is generally considered a detrimental inconsistency rather than a functional part of your intended neck tension. Technically, yes, if your bullet is seated deep enough to reach it, the donut adds a significant amount of "grip" or interference. However, it is an uncontrolled tension.

 

[Bottom Fodder]

While it is physically part of the neck area, it is generally considered a detrimental inconsistency rather than a functional part of your intended neck tension. Technically, yes, if your bullet is seated deep enough to reach it, the donut adds a significant amount of "grip" or interference. However, it is an uncontrolled tension.

Ok not disagreeing but thought you could control donuts with inside neck reaming
Fill free to correct me

 

[ShaunBrady]

Ok not disagreeing but thought you could control donuts with inside neck reaming
Fill free to correct me

You can, but now we're talking about an advanced version of neck turning that most really hoped to avoid when they bought good brass and did the one big thing to control SDs. It's also a misery many bring on themselves by running tight necks because they believe it improves accuracy or they're trying to avoid "overworking" brass. It's a good example of something that'll be easier to see on the chrono before it'll show up consistently in group size. If they want to wait until a box of bad groups ruins their day, bless their hearts.

 

[JEFFPPC]

Did your qroups shrink?

A few less outliers. It did help a little at 1000. More consistency. I think you get to the point your doing what you can to pick up a point or two.When your shooting at a 1 inch 10 ring at 500 yards your looking for grains of sand not boulders. Are you willing to do the work to cover all the bases you think might help? Once again it depends on disciplines.Will it make a 1 inch gun a .2 gun? Of course not. Will it cover up ignoring flags? No. But if your very competitive and looking for that little nudge, you do what you hope might give you that 1 extra point.

 

[Shooter13]

A few less outliers. It did help a little at 1000. More consistency. I think you get to the point your doing what you can to pick up a point or two.When your shooting at a 1 inch 10 ring at 500 yards your looking for grains of sand not boulders. Are you willing to do the work to cover all the bases you think might help? Once again it depends on disciplines.Will it make a 1 inch gun a .2 gun? Of course not. Will it cover up ignoring flags? No. But if your very competitive and looking for that little nudge, you do what you hope might give you that 1 extra point.

I agree, it is the small stuff! In UBR with a 30 cal at 100 yards we are shooting at a dot that is .050" so while it is "only" 100 yards the small stuff matters!

 

[GetReal]

Everybody is missing the most important indicator, look at your results on targets…. That’s the most important indicator and what was done before everyone has gotten a chronograph (or could afford one anyway).

The target AT DISTANCE. I cant begin to tell you the # of great 100yd targets Ive had where that load shot like crap at distance. SD/ ES matter. Both need to be good at 100 yd. Low SD can hide a single bad round, where ES will show that.

Thats why ES is always my final load check... three separate 100 yd groups on 3 different days. Then I test at distance. The load with low SD *and* ES has almost always shot good at distance for me.

Of course, ANY load that shoots 0.5 - 0.75 moa at 1000 yds is good enuf for me. (grins)

 

[JEFFPPC]

Here is something most never think about. At 78 I have found regardless of the scope I can't see as well as I could 10 years ago much less 40 years ago. Last 6 years about 95 percent of the time when shooIngt my head shakes, some days not so bad, some days I want to scream. So you try to compensated little bit by doing all the little things. But if you love to shoot and you have competitive genes you keep pushing forward. I guess the smart guys move to a less demanding hobbty. Glad I'm not a smart guy. So if ironing my flag tails will help, I will ask my wife to do it, lol.

 

[Straightshooter1]

Here is something most never think about. At 78 I have found regardless of the scope I can't see as well as I could 10 years ago much less 40 years ago. Last 6 years about 95 percent of the time when shooIngt my head shakes, some days not so bad, some days I want to scream. So you try to compensated little bit by doing all the little things. But if you love to shoot and you have competitive genes you keep pushing forward. I guess the smart guys move to a less demanding hobbty. Glad I'm not a smart guy. So if ironing my flag tails will help, I will ask my wife to do it, lol.

Yeah, at 78 I too just don't have the eagle eye sight I once had. The cataracts and having bifocals was making it frustrating to get good results. Am so glad I had that all taken care of a little over a year ago now. It's so nice to get a nice clear image through my scope now, even better I can see clearly my pistols iron sights. and not have glasses I had to fight with. Life is good!

 

[dellet]

Seated depth and powder charge, they work either together or against each other. These things will cause double and triple digit changes in your ES/SD numbers.
Thats the simple answer to an over simplified question.

Unless extreme cases, neck turning, weighing primers, changing primers……..all are generally single digit changes.

A good argument good be made that precise measuring tools are the answer. If you can’t measure the change, you’ll never know what caused it.

And finally, the answers are likely to reverse with a different lot of components, once the basics are covered.

 

[shoot4fun]

note to self.....self DO NOT participate in any threads started by Bottom Feeder

I see what you did there! That's funny!!!!

 

[Fuj]

Glad I'm not a smart guy. So if ironing my flag tails will help, I will ask my wife to do it, lol.

Got me chuckling there a bit......LOL

Digging around for a target that shows an extreme in ES/SD's......I was doing
a powder work up with the 7.2 creation using V-135 and Sierra's 100gr FB
varmint bullet......On that target you'll see 2 groups with real low numbers
and about the same group shape. In between those two is one with a quite
a bit larger number, but gave a real nice round shape......When I took them
to the upper 300 yard range, The group with the high numbers still shot on
the round side, where the other two strung out. The higher numbered ES/SD
measured the smaller of the two groups at 300.