Primer Weight

[Sumtoc]

I've read/watched all sorts of info re: sorting primers by weight but still have questions for you guys. Thanks for your help.

For LRPs what is the range of weight differences that you will use/shoot together for a F-Class 1K match?

I've attempted a couple of tests and can't achieve meaningful results. I weighed 200 Federal 210Ms, got a rough bell curve of distribution with the difference between the extremes being .24 grains. I shot those extremes expecting to see a noticeable difference in MV but didn't. Nothing notable on paper either.

So this leads me to consider several explanations and options:

1) The variance of the test batch is not great enough to matter (hence the first question).
2) The 284 cartridge (and capacity) is larger and so more variance is required to see a difference
3) Maybe I should sort out the really extreme outliers and not worry as much about smaller differences. If so, what weight difference would constitute an outlier?

Thanks

 

[dcali]

The smaller the effect, the more you're going to have to shoot to reliably see it. I think it's safe to say that primer sorting will have a very small effect - probably too small to test.

 

[Jefferson]

try minimum 20 shots with different primer manufacturers

choose one

your done

primer weight is just noise as there are too many other variables to degree the effect of small insignificant primer weight changes

look for primer defects
similar to sorting bullets you can look for the out of spec ones

the consistency of your grip to the 1 inch pound is way more important
the BREAK AWAY FRICTION in a bench gun is way more important


BUT thanks for asking now buy my book on mental shooting toughness

 

[JEFFPPC]

Depends on the accuracy level you require. In my case I weigh to 1 piece of Varget. So using the example given of .24 which is about what I have found, that is12 pieces of Varget. Makes no sense to weigh to 1 piece and than throw in the variable when shooting beyond 300 yards. Depends on your game and volume of ammo needed I think.

 

[Bottom Fodder]

The closest I come sorting primers is I “try” to use all same lot# in a match
to me I’m A bigger variable than the variable weight of primers has on my shooting

 

[SteveUrban]

CCI BR primers, I just load them, no sorting required. I do sort Rem LR's for my Black Powder loads. The lot I have is from 5.0-5.4 grains with most being 5.2 or 5.3 that I use for matches.

 

[Fuj]

The smaller the effect, the more you're going to have to shoot to reliably see it. I think it's safe to say that primer sorting will have a very small effect - probably too small to test.

I sort the large primer and compete, sometimes long range steel,
sometimes up close an personal. If you have a way under or over
charged primer., it's the same as too little or too much powder for
your tune. There is no doubt in my mind that I have curtailed my
fliers if all other things are equal.....I sorted some Federal Champions
I had just in case I run low again on BR2's. The sort went at a high
0f 5.32 grains to a low of 5.18. That's quite a bit considering how
much just one tenth of powder can skew your tune let alone a primer's
1/10th has much more energy. Take a heavier primer coupled with
a tad heavier charge, you'll send it high. just the opposite you'll
send low. If you compete, don't leave it on the table.......

 

[Rocketvapor]

The metal in the primer (almost perfect) and the priming compound (again almost perfect),
are from two non related processes. There would be a distribution of both. Small spread because they are almost perfect, but a distribution none the less.
The odds of the two distributions lining up the same so that light metal and light compound always end up creating a light primer (same for heavy stuff) might be valid for an extreme outlier. Maybe one or two per thousand.
A light metal, cup/anvil could end up with a heavier charge and be a mid-weight primer. Or, a heavy metal, light charge also being right near the mean.
You need a large enough sample to find EXTREME outliers with the hope that they also contain EXTREME charges, which probably is what you are looking for.
Sample size MUST be large enough to define an OUTLIER.
Probably won't find all light/heavy charges of compound.
But, each one could have been a "9".

An example is an old exercise I did sorting steel case, bimetallic X39 ammo.
Case weight had a range of about 5 grains, projectile about 2.5.
Total cartridge weight had a range of close to 7.5 grains.
Pulled down a BUNCH to reload with better bullets.
Only extreme light weight cartridges had both light cases and light projectiles.
The same for extreme heavy cartridges.
Some of the midweight cartridges had LIGHT and Heavy parts mixed.

 

[antunRC]

Here is a test I did on my 284 Shehane.

 

[Rocketvapor]

@antunRC
Did you keep track of the one light and two heavy primers?
Do you think 100 was enough to find the worst?

I did a box of 1000 CCI 450 SRP.

 

[antunRC]

@antunRC
Did you keep track of the one light and two heavy primers?
Do you think 100 was enough to find the worst?

I didn't keep track of the one lightest one and two heaviest primers, but I have tested worse case scenario, difference in weight between min/max group was about 0.16gr minimum.

"Do you think 100 was enough to find the worst?"

I think for what I was looking to test, sorting 100 primers was good enough.
I might consider re-taking the test in the future with a larger sample size.

 

[Dave Way]

I will continue to sort primers but I would prefer that those I compete against don't.

The same goes for weight sorting brass, neck turning multiple times, weighing powder to the kernel and making sure all shoulders are bumped to 1/2 a thousandth consistency. No sense in any of you doing all of that! See you at the next match.

Dave.

 

[dcali]

The metal in the primer (almost perfect) and the priming compound (again almost perfect),
are from two non related processes. There would be a distribution of both. Small spread because they are almost perfect, but a distribution none the less.
The odds of the two distributions lining up the same so that light metal and light compound always end up creating a light primer (same for heavy stuff) might be valid for an extreme outlier. Maybe one or two per thousand.
A light metal, cup/anvil could end up with a heavier charge and be a mid-weight primer. Or, a heavy metal, light charge also being right near the mean.
You need a large enough sample to find EXTREME outliers with the hope that they also contain EXTREME charges, which probably is what you are looking for.
Sample size MUST be large enough to define an OUTLIER.
Probably won't find all light/heavy charges of compound.
But, each one could have been a "9".

An example is an old exercise I did sorting steel case, bimetallic X39 ammo.
Case weight had a range of about 5 grains, projectile about 2.5.
Total cartridge weight had a range of close to 7.5 grains.
Pulled down a BUNCH to reload with better bullets.
Only extreme light weight cartridges had both light cases and light projectiles.
The same for extreme heavy cartridges.
Some of the midweight cartridges had LIGHT and Heavy parts mixed.

For what it's worth, I'm aware of a few people who tried to separate out the metal components and found that their weight variation is almost nil. If memory serves, you might be able to search it up on this site. Basically, the measurable variability of primer weight is almost entirely due to compound weight variation. I've not done it myself because who has time for that, but that's the conventional wisdom. Milage may vary.

 

[Rocketvapor]

That would be great, making sorting mean more.
I think I saw that with fired and cleaned primers.
Again, it's finding the Extreme heavy/light with a large enough sample.
I'll try and find that thread

 

[Dave Way]

That would be great, making sorting mean more.
I think I saw that with fired and cleaned primers.
Again, it's finding the Extreme heavy/light with a large enough sample.
I'll try and find that thread

This may not be the one that you are looking for.

Weight sorting primers-Test

It's winter time, I'm bored and it's a great time to do tedious things before next shooting season. I have never weight sorted primers but have a few friends who do. When I asked them if it helped they said they weren't sure. The reason was they never knew if the variation was the priming mix...

forum.accurateshooter.com

Dave.

 

[Rocketvapor]

Dave,
I'll check that one out but tonight I'm finishing up for a practice session for the wife and I tomorrow.
Do I SEE an improvement sorting primers? Probably not.
A better shooter might see a couple more X's with his/her/their cleans.
@ 600 I'm an almost moa shooter (get some 9's). Sometimes many.
Wife is a little better buts gets these random 1/2 MOA out of group fliers.
I'll do whatever I can to trim her groups by an 1/8 MOA.
We'll see if her 100 yd, 300, and 600 dope is OK with the new rifle.



I'm retired, and it costs me time.
I luv you guys that load to one kernel.
+/- one kernel of SB 6.5 is wishful thinking with my scale, usually +/- 2.
Sometimes it will count up with one kernel, sometimes not.

 

[quest450]

Dave, now the cat is out of the bag

I don't think this is a big secret but IMO if you compete in 600 or 1K benchrest and trying to shoot really small everything matters but I'm glad most of the shooters think otherwise

 

[Doom]

Brian Zolnikov has a Youtube channel (The Witchdoctor) and has done some testing on primers that is worth viewing. Brian has a good handle both on test design and analysis.

 

[JFrank]

With all do respect, I do my own testing and not rely on u tube for direction or results.

The target is king…

 

[quest450]

With all do respect, I do my own testing and not rely on u tube for direction or results.

The target is king…

BRAVO !!