Weighing primers !

[TIMO]

When you weigh primers how do you know where the weight is?? Could be in the cup, Could be in priming compound??

All, a good read on this post & input. My cat helps as well.

Just a thought on the primer weight, compare them with once fired to see and find the average of the cup.



Tim

 

[Dr. Matt]

@Dr. Matt
What is the model of that scale?
Is it this one:

Hornady Precision Lab Scale for Handloading Perfectionists - RifleShooter

The new Hornady Precision Lab Scale answers the needs of the perfectionist hand-loader. Tested by Joseph von Benedikt.

www.rifleshootermag.com

@SteveOak
What scale do you use to weigh primers?

 

[Dr. Matt]

I use this Hornady

 

[Dr. Matt]

@Dr. Matt

That scale has neither the precision nor the accuracy to measure primers to two decimal places. I would not trust it to one decimal place.

I kinda feel the same way, but it's what I have.

 

[Rocketvapor]

To sort primers you don't need accuracy, you need resolution and repeatability.
Zero then primer weight indicated needs to be repeatable.
If a 3.62 grain primer repeatably reads 3.66 and a 3.72 grain primer repeatably reads 3.76grs,
then one is lighter than the other. A GOOD check weight (more useful than a full scale cal weight) can be used to fine tune the actual weight (using the scale as a comparitor).
Scale linearity (specified over entire scale range) also doesn't enter in weights nearly the same.
Primer sorting into bins (not culling out extremes) probably requires something better than a 1mg resolution.
The Hornady scale shown, or even the FX120 should be more than adequate to find outliers.

 

[JFrank]

I kinda feel the same way, but it's what I have.

What is the resolution when in gram mode ?

 

[Rocketvapor]

The real question should be
"will it resolve to one kernel of Varget "
The gold standard of reloading scales .

We uniform flash holes, primer pockets, measure primer crush, but resist weighing primers.

 

[SteveOak]

To sort primers you don't need accuracy, you need resolution and repeatability.

The Hornady scale has insufficient resolution and poor repeatibilty.

 

[Rocketvapor]

What is the resolution of the Hornady scale?
Not trying to defend the scale, or the 120i, as I have an A&D EJ-54D2 and a A&D ER-182A AND many very precise Check Standards (instead of Varget) to verify my weighing.

One problem I find with Varget is I get from 135 to 145 counts per granule on the 182A.

Get check weights near your target that are more accurate than your scale or desired results.

Pretty close on the 182A



I weighed out 30 grains on the 54D2, then checked on the 182A.

I think I know how well my weighing equipment works.

 

[Rocketvapor]

For those that think they know how well their weighing technique works,
Use adequate check standards, You don't need the best, just better than what you need


And check your scale at several points near what you weigh.
This is the EJ-54D2 on the HIGH range.


I'm beginning to realize why most don't go down the primer sorting rabbit hole

 

[Straightshooter1]

In all these tests, one of the things I don't see being done to get good primer test results is to be sure to use cases with the same case volumes. We know that variance in case volumes will affect velocities significantly. And while there's a correlation in case weight to volume, to test primers, I'd want to directly measure the actual case volumes and use only those with volumes that were the same in order to mitigate that variable as much as possible. I wouldn't trust primer testing otherwise, but I guess, that's just me. ¯\_(ツ)_/¯

 

[JFrank]

No, the question I asked was the resolution in gram mode, I ask this because i see less drift when sorting in gram mode with strain gage scales. I see on the Hornday scale specs it resolves .04 gr or .002 gram and should be well within the need of primer sorters.

 

[Fuj]

This is what I use just for primers. It has a .02 grain resolution.
No 5.24 BR2's in pic. I already loaded the last of them for the last
match, and finished the last few off with the 5.22's......I'll note that
this last brick had a spread of 5.34 to 5.18 grs. A good 80 percent
of this particular brick were 5.26 grs. and lower.

 

[Rocketvapor]

Who measures case volume on their match rounds (and doesn't measure primer weight)?
I'll admit I'm not a good enough shooter to see all the variations in speed and POI from primer sorting.

There's two lines of thought with sorting.
Sorting into narrow bins by weight, or just eliminating the gross outliers.

I wouldn't want one of these show up in a match,


I did a test of 10, the another test of ten, then a test of 30.
The difference between high and low outliers was about an MOA @600yards.
The difference between adjacent bins (0.02gr) is really too small for me and my shooting ability.
I now see average velocity differences when shooting a practice session with sorted 3.66gr primers and 3.70gr primers, but still have trouble staying within an MOA at 600.
Maybe when I'm better.

Another thought on tight sorting of primers by weight;
There has to be a range of weight of the metal parts, and a range of weight of the mix.
Two primers of the same weight could have heavy metal/light mix or light metal/heavy mix or mean metal/mean mix.
They are separate processes that make up the final product.
It seems probable that the few percent light/heavy extreme outliers have light/light or heavy/heavy combinations and are at the tails of the individual process distributions.

 

[JEFFPPC]

Of course no one MUST weigh primers. We are all free to put in x amount of work, or not, as we feel fits our loading process.

 

[JFrank]

Of course no one MUST weigh primers. We are all free to put in x amount of work, or not, as we feel fits our loading process.

The crazy part is that guys spend hundreds on annealing machines, high dollar presses and primer seaters etc. with little to no evidence of positive results on the target yet refuse to spend a few minutes to cull out extremes that we know affect the target.
Go figure.

 

[Doom]

I seen enough tests run by various people, mostly based on High/Low weight velocity measurements to convince me that there is a definite correlation of primer weight to velocity. It actually make sense in that the pressure produced by the primer charge is going to impact how much the powder will have to contribute to the release of the bullet. Less powder energy in bullet release shows up partially as velocity.

With that said, it would make sense that 223Rem shooting a Rem 7-1/2 (or a 450) will have a greater effect on velocity than a 308Win with SRP shooting the same primer.

 

[Joe Salty]

Well this is interesting! Let me ask you this if your shooting 1000 Yard like myself. I'll tell you what I don't won't a Primer that weighs 3.68 in with my record rounds that weighs 3.88. You can do what you like, but I'll take the time to weigh mine.

Joe Salt

 

[R.Morehouse]

Can you successfully sort primers on a tuned beam scale?

If not, how much money does it cost to do it correctly, electronically.......Thank You

Regards
Rick

 

[JFrank]

Can you successfully sort primers on a tuned beam scale?

If not, how much money does it cost to do it correctly, electronically.......Thank You

Regards
Rick

It’s tough on a beam scale, however I’ve used a cheap Bald Eagle strain gage scale set on gram mode because it had less drift. When I finally picked up a FX120 I compared the previously weighed primers to the results on a milligram balance and to my surprise they were the same weight, so yes it can be done on a budget scale.
Just a side note; somewhere I read a spec sheet that listed CCI 450’s in grams. ( .239 g ) I can’t seem to find it again, oh well.