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Weighing Primers?

HTSmith

Silver $$ Contributor
I tried weighing some primers this morning for the first time. The primers were CCI450's that I use in my 6BR's. I just picked out 20 from a tray of 100 and got weights ranging from 3.64 to 3.71 Gr with the majority at 3.68 Gr. I not a stats guy at all and I'm pretty sure this sample is too small to be valid for the whole lot--but it seems to me that this variation is too small to bother with. Did I just get lucky with this lot of primers? For those that weight sort regularly, what sort of weight limits do you use for your sorting? I don't know what I don't know. Thanks
 
HTSmith said:
I tried weighing some primers this morning for the first time. The primers were CCI450's that I use in my 6BR's. I just picked out 20 from a tray of 100 and got weights ranging from 3.64 to 3.71 Gr with the majority at 3.68 Gr. I not a stats guy at all and I'm pretty sure this sample is too small to be valid for the whole lot--but it seems to me that this variation is too small to bother with. Did I just get lucky with this lot of primers? For those that weight sort regularly, what sort of weight limits do you use for your sorting? I don't know what I don't know. Thanks
Click to expand...

I had .14 spread. The primer test attached only looks at Fed 205M primers, however you can see from the bell curve, they are really consistent.

I determined, in my ppc, it actually did make a difference in vel.
Clay
 

Attachments

@HTSmith
While your only around 2% variation from a sample size of 20, what if you continue on and it doubles? (or worse?)

I have weight sorted Lot's that likely did not need sorting, that had little variation (like say 2 to 4%). But have also sorted Lot's of the same brands/types of primers that averaged +5%, and Lot's that were much worse (7 to 10%). The biggest thing I am after when weight sorting are the "extremes" off each end. And in finding them, why not keep the rest qualified into there weight batches, and use them in sequence of there weight.
Again, just my 2-cents.....
 
I guess that if one has the cash, one can buy a scale that'll weigh just about anything right down to the nit on a nub on the nut of a gnat. The only question is, is it worth the trouble and expense.

For that kind of accuracy on a consistent basis, one has to have a special lab, temperature and humidity controlled, shielded from electronic noise, perfectly filtered power, etc.

And of course a good data set to justify the effort.

How I would separate out the projected improvement from all the other factors contributing to group size is beyond me. In my experience, daily atmospheric density changes have more to do with my success at the range. But that may be just because I can't shoot like the rest of you'z guys. :rolleyes:
 
you keep talking yourself out of it, we will keep winning.
your assumptions are not true.

Texas10 said:
I guess that if one has the cash, one can buy a scale that'll weigh just about anything right down to the nit on a nub on the nut of a gnat. The only question is, is it worth the trouble and expense.

For that kind of accuracy on a consistent basis, one has to have a special lab, temperature and humidity controlled, shielded from electronic noise, perfectly filtered power, etc.

And of course a good data set to justify the effort.

How I would separate out the projected improvement from all the other factors contributing to group size is beyond me. In my experience, daily atmospheric density changes have more to do with my success at the range. But that may be just because I can't shoot like the rest of you'z guys. :rolleyes:
Click to expand...
 
How much of primer variation is do to the weight of the cup, the anvil, the seal, or the propellant? I would think that the weight variance of the other components, besides the propellant, would not make much if any difference. May be good to weigh one, fire it, clean and weigh the other parts to see what percentage of the total weight they are.
Primer.jpg
 
T-shooter said:
How much of primer variation is do to the weight of the cup, the anvil, the seal, or the propellant? I would think that the weight variance of the other components, besides the propellant, would not make much if any difference. May be good to weigh one, fire it, clean and weigh the other parts to see what percentage of the total weight they are.
View attachment 1162877
Click to expand...

the doc attached to post 3 covers that.

CW
 
I have been down this road before after reading these post .
I started weighing my Primers . I then tried to to figure out ! why the light were light and the Heavy Heavy .
Remove the anvils weight them ? Put the light ones on the side . Now weight the cups !
Match the Anvils with the Cups !!!!
What to do with the light ones ???
Weight the light ones , balance then out by adding flacks of Bullseye .
This is a job for the Level One Reloader .
This will not work .....
 
this is where statistics and probability come in to play with real world testing/results.
no it is not a perfect system, but is better than not weighing them.
see the test results. its ok not to do it, it gives some of us a slight advantage.

T-shooter said:
How much of primer variation is do to the weight of the cup, the anvil, the seal, or the propellant? I would think that the weight variance of the other components, besides the propellant, would not make much if any difference. May be good to weigh one, fire it, clean and weigh the other parts to see what percentage of the total weight they are.
View attachment 1162877
Click to expand...
 
I've got a seating depth test all loaded up.
Before I made the decision to try primer sorting.
Talk about timing :(
Somehow I think there will be some second guessing after I shoot these,
and the local range is still flooded.
Waiting is hell.
 
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