Do you weight sort primers?

[Dave Way]

So this is what 1,000 Federal 205M primers look like after you weight sort them to .001 Grams.



No, I didn't count each group but you can see a very nice bell curve. The total variation was .008 Grams.

The average weight of the cup and anvil from some prior testing I did was .215 Grams so the priming compound should vary from 0.030G to 0.022G, a 36% variation.

http://forum.accurateshooter.com/threads/weight-sorting-primers-test.3966861/

My question is do you weight sort primers and why or why not?

I'm sure some of you are wondering, it took 2 hours and 15 minutes to sort them.

Dave.

 

[Ned Ludd]

There have been a few recent threads on this that might be of interest to you. topic: http://forum.accurateshooter.com/search/41987588/?q=weighing+primers&o=relevance

Just out of curiosity, what was the standard deviation on the average cup+anvil weight of 0.215g? Just trying to get a feel for what the variance of cup+anvil weight was as compared to the variance in the weight of priming compound alone.

 

[hrlincoln]

Funny thing, I just did this the other day mainly out of curiosity after reading that same thread. I weighed 1000 BR4s...in grains though. I too used an FX-120i..they ranged from 3.70 - 3.80 and looked a lot like your distribution. I guess the targets will tell us why, or why not.

 

[Medic505]

I don't. That said, it would be very interesting to see chrono results if you took 5 from the far right vs 5 from the next to far left. Inquiring minds want to know....

 

[Erud]

No.

 

[tom]

Cronographs are for people who can't tune a rifle. Shoot them 5 lightest, 5 heaviest in ALTERNATING sequence at 1000 in a tuned rifle. You will see a point of impact difference or you won't. This will tell you if you're wasting your time or not.


These threads all go to the velocities, and charts....and all of it gathered with a consumer grade chronograph. I shoot at paper at 1000 and record everything on my lab radar. More than 80% of the time, "$hit just don't add up".


Tom

 

[F Class John]

I absolutely do now. I’ve seen enough data on my end to prove it can make a difference and for what little time it takes to do I believe in it.

Here’s 700 primers. BR2. There were about 10 that fell above or below the bags that you see here for a total extreme spread of 5.02 all the way to 5.36. But the majority of them fell between 5.14 and 5.32 With the largest concentration between 5.22 and 5.28 as seen by the two bags in the middle. You can see how I group them if you look at the bags in the pic.

 

[Bc'z]

Cronographs are for people who can't tune a rifle. Shoot them 5 lightest, 5 heaviest in ALTERNATING sequence at 1000 in a tuned rifle. You will see a point of impact difference or you won't. This will tell you if you're wasting your time or not.

Tom

You wont.
Weighing primers is a joke!!
Just as brass varies in weight so does all the components in each primer.
For brass it makes sense as a piece of brass with a lower internal volume will create more pressure causing shot to hit high, whereas a piece with a higher case capacity and same charge weight will have a lower pressure and point of impact.
Now back to primers...
Without the ability to individually weigh each component of the primer by itself your just guessing. Your weight variable came from which component?
Cup?
Anvil?
Charge?
Foil?
Sorry you wasted your time in this exercise in futility.
Got my info from a physics professor.
Yup I'm a Scott parker fan.

 

[tom]

You wont.

Ohh?

 

[JFrank]

Cronographs are for people who can't tune a rifle. Shoot them 5 lightest, 5 heaviest in ALTERNATING sequence at 1000 in a tuned rifle. You will see a point of impact difference or you won't. This will tell you if you're wasting your time or not.


These threads all go to the velocities, and charts....and all of it gathered with a consumer grade chronograph. I shoot at paper at 1000 and record everything on my lab radar. More than 80% of the time, "$hit just don't add up".


Tom

Tom
Great point “
Are you guys getting cabin fever over there?

Daughter said it was 7 degrees in Libby yesterday morning.
I’m looking forward to that

Jim

 

[tom]

Jim,

Negative 3 this morning....Yeah I'm about ready to flip out soon lol.

Tom

 

[dmoran]

Primers are like sanctioning bodies; some Lots are okay, and some Lots need sorted out !.!.!

 

[fyrewall]

If you don't really know go for it - you might determine your pursuit is a dead end but save your data anyhow.

Looking at this stuff the following link shows some actual testing:
https://arxiv.org/ftp/arxiv/papers/1102/1102.1644.pdf

Fig 3 in the report provides total mass - like the whole works, cup, anvil, wafer, explosive and blast pressures are shown on the graph - looks sort of flat - 10 degrees? Fed 210M

Fig 4 shows the mass of the explosive only - the graphs are remarkably similar ("strongly correlated") indicating relatively uniform components - also looks sort of flat. Fed 210M - hopefully the same primer before & after - what about variations in the tiny amount of residue? (black stuff)

"since the slope of peak pressure vs. mass is 10.5 psi/mg the best we could expect is a variation of 10.5 psi for a group of mass sorted primers with 1 mg. variation." about 5.7 percent of 176.5

Almost finally - "However, it should be pointed out since most of the slopes of peak primer blast pressures are between 8 and 20 psi/mg achieving variations in peak blast pressure below 10 psi would likely require sorting primers into groups on the order of 1/4 to 1/2 milligram" Concluding with weighing on some super sensitive $1,000 lab scale.

Sounds too fussy to me - or possibly that is why I regard my self as a casual shooter. Straight from the primer box with the little pockets to Lee press mounted primer seater to my brass cases.

As a extraneous side note - I think the way Federal packages their primers would offer more protection against an explosive chain reaction.

 

[JMayo]

I do. I want to weed out the outliers ....
The "nut on the butt" is the cause of me not being able to prove it's worth... But they are mine and I'll do what I want with em.
So ... Kmb you NAaa sayers !

 

[Rsadams]

No...

 

[ShootDots]

I can see the worth / value of:
1.) case weight sorting; 2.) weight sorting primers; 3.) sorting bullets to: weight, BTO and OAL 4.) annealing; 5.) weighing powder charges down to the individual kernel and 6.) what we would consider complete case preparation.. They ALL have value and would contribute to the consistent creation of a loaded round. Obviously, the more consistent, the better chance of a higher degree of accuracy..
Now the question becomes "To what degree are we willing to go in pursuit of extreme accuracy"? To me I love accuracy! However, I also loathe tedium! So, for myself, I have to go only so far as to keep a high degree of accuracy BUT not so far as to render the process "no more being fun due to boring, labor intensive actions". I have to have fun and the tedious nature of all that "sorting" diminishes my fun. So, in order to continue having fun, I limit myself to certain "prep items" that promote an accurate round>>>but not to the "inth" degree.. We all have our likes, dislikes and level of tolerance to get where we desire to go..

 

[Bc'z]

Ohh?

So I was informed I took on one of the most accomplished 1000 yard shooter and product testers in my last post.

As firewall more articulately and eloquently put it
How can one possibly weigh and discern what is giving the weight variance?

@dmoran stated some primers just need to be sorted by weight.
If you've come to the conclusion they needed to be sorted, wouldn't you move onto a better lot and use the questionable lot for fire forming?
Hey you guys are far better than me without question!
So what is the cost of accuracy in time and money?
As I'm also a casual shooter, but with just enough common sense not to dig my rabbit hole any deeper than it needs to be.

Enlighten me and others please.
As we'll all gain more from your knowledge and experience.

 

[T-shooter]

Sounds like a lot of work that may or may not pay off. When weighing you are weighing the entire assembly. The only part that really matters is the propellant, explosive. If it could be proven that heavier primers produce more power, then it would be beneficial. Probably time would be better spent measuring the volumes of the cases. I used a different lot of cases that ended up being 7% larger in internal capacity. The muzzle velocity dropped off an average of 37 fps with everything else being the same, plus the group size opened up quite a bit.

I like to test so when winter is over, I want to load some ammo that is as exact as I can measure every component. Weighing some primers would take that long.

 

[One Shot One Thrill]

Cronographs are for people who can't tune a rifle. Shoot them 5 lightest, 5 heaviest in ALTERNATING sequence at 1000 in a tuned rifle. You will see a point of impact difference or you won't. This will tell you if you're wasting your time or not.


These threads all go to the velocities, and charts....and all of it gathered with a consumer grade chronograph. I shoot at paper at 1000 and record everything on my lab radar. More than 80% of the time, "$hit just don't add up".


Tom

Hey Tom,
I thought the same thing until I started recording the terminal velocity as well.

 

[Mulligan]

Jim,

Negative 3 this morning....Yeah I'm about ready to flip out soon lol.

Tom

Come on south for our match the 9th of March. Grass is starting to green up a bit, no snow. We are only a day drive from you and lots of sun. Match day is likely to be about 50* with a 40% chance of light showers.
Not great, but it is March in the Rockies!
CW