Vertical Dispersion - Weighing Primers

[6bra1k]

Well I haven’t won and really don’t expect to,considering the level of competitors at DC I may never win and that’s fine as well. I did manage to reduce my aggs by 3 in over the last 6 targets so that’s an improvement I look to build on.
Nice to visit with you last June at the range and hope all is well.
Jim

pm me

 

[Alex Wheeler]

Well I haven’t won and really don’t expect to,considering the level of competitors at DC I may never win and that’s fine as well. I did manage to reduce my aggs by 3 in over the last 6 targets so that’s an improvement I look to build on.
Nice to visit with you last June at the range and hope all is well.
Jim

Keep showing up to DC and you will win. I have not seen anyone put in the effort not be competitive.

 

[Dave M.]

Hey Guys,

I'm not looking to start a debate on the merits of weighing primers, or if it's worth the time investment. I've already decided to give it whirl, and I've weighed out 1,000 of them into groups separated by .02gr mostly (with some extreme outliers culled entirely).

I will say I was pretty surprised by a couple of observations. First, there was way more variation than I was expecting to find. I had a range from 2.28gr all the way up to 2.52gr. Most fell right around 2.40-2.46gr; nice little bell-curve.

It's not my intent to mix any weight groups; just going to load all those that weighed the same together.

That said, I'm not going to get a chance to shoot these until my next match, but as of late I've been struggling a bit with vertical in my load. It'll hold 10-ring vertical consistently at 1,000, but it's not as good as I see from some of the top guys.

I've played around with depth in .002 graduations, but can't seem to tune it any tighter, so here we are. I think my powder node is on point as I'm in the usual velocity range for my barrel length/bullet combo, and generally speaking the gun is shooting quite well.

My question: To those that have weight sorted primers, how much (if any) improvement in vertical did you see?

Bring on the discussion; my body is ready.

Components:
200.20X
N150
Lapua Plama - turned .014"
CCI 400s
.0015 'interference fit'
AMPed every firing

No offense intended here Mike, but I highly doubt that 99.99% of shooters would be able to shoot the difference and even if you could, I doubt that you will be able to show statistically significant results clearly showing a difference of weighing or not weighing primers. I will be watching this discussion closely to see the results. I can only imagine how much time this could add to my reloading regime if added, so potentially I’m hoping there is no correlation to be shown.
dave

 

[JMayo]

With my 6bra too much neck tension made my groups spread. Seems Most here seems to talk about more neck tension being the go to but that's not my experience.

 

[BJung]

I've read part of all these threads. There are too many. Has it been asked whether the cup and anvil weight are consistent? Has anyone weighed the spent primers to see if they are the same weight? Weighing primers for consistency under these conditions would be like grouping brass by weight when after measuring the volume, you find variations within the same grouping, or atleast I have.

 

[6bra1k]

No offense intended here Mike, but I highly doubt that 99.99% of shooters would be able to shoot the difference and even if you could, I doubt that you will be able to show statistically significant results clearly showing a difference of weighing or not weighing primers. I will be watching this discussion closely to see the results. I can only imagine how much time this could add to my reloading regime if added, so potentially I’m hoping there is no correlation to be shown.
dave

its not 99.99 that cant or dont, it is ALL THE PEOPLE THAT COMPETE IN 1000 BR. it has been tested and PROVEN.
period done over.
what you BELIEVE has little to do with PROVEN DATA.

 

[BJung]

Did you read post #174

That's a really small difference..

 

[INTJ]

Well I haven’t won and really don’t expect to,considering the level of competitors at DC I may never win and that’s fine as well. I did manage to reduce my aggs by 3 in over the last 6 targets so that’s an improvement I look to build on.
Nice to visit with you last June at the range and hope all is well.
Jim

I too enjoyed @dmoran visit last June. He looked at my tuning ladder for my 300 WSM, and said pick that powder charge. That weekend I shot a 4.3 and a 3.8 HG group, both 100s. One might infer that he knows what he is talking about......

Maybe he can come out in the cold for the match at the end of this month, since I have new barrels on both my HG and LG.

 

[Dave M.]

its not 99.99 that cant or dont, it is ALL THE PEOPLE THAT COMPETE IN 1000 BR. it has been tested and PROVEN.
period done over.
what you BELIEVE has little to do with PROVEN DATA.

Go for it. Do it. More power to you.

 

[Dave M.]

Go for it. Do it. More power to you.

I suggest you do the following experiment at 1000 yards. Load 20 rounds identical, with the exception that 10 use primers on the extreme low end of weight, abd the other 10 use primers of the extreme high end of the weights. Then color the primers on the light ones with a red sharpie. Now have someone mix them up really good and put them in you loading block. Shoot all 20 on an e target without looking at the primer while you load or unload rounds. Then we can tell really quickly whether the extreme of the population in a random order blind test have any statistical significance in vertical whatsoever. I say if it makes you feel good and you have the time, then go ahead and do it. People often have rituals or processes that when done increase their confidence. I once knew a ridiculously good shooter with many wins that was convinced that he shot better when he colored the tips of his rounds green. I think the only way we could be assured of beating him was to hide his Shapie. Lol

 

[Sandstorm]

Dave M. said:
So your implying the because I felt so good about my new paint job on my newly built rifle.
I went out and won the maiden competition....and no other reason.
Hmmmm..you know this game is a lot in the head anyway..and confidence plays a big part.
When I feel good I have a better chance of winning...(and I will buy that any day,) and weigh sorting
primers dont hurt none either...lol

 

[Dave M.]

Dave M. said:
So your implying the because I felt so good about my new paint job on my newly built rifle.
I went out and won the maiden competition....and no other reason.
Hmmmm..you know this game is a lot in the head anyway..and confidence plays a big part.
When I feel good I have a better chance of winning...(and I will buy that any day,) and weigh sorting
primers dont hurt none either...lol

Like I said, I wasn’t trying to hurt the previous posters feelings (6Bra1K) when I stated by all means, if you have the time to do it and it increases your level of confidence on the firing line, then go ahead and do it. And yes, I do believe that your new paint job on your rifle factored into you winning. It increased your confidence and allowed you to focus on your fundamentals and relax.

 

[Bc'z]

Like I said, I wasn’t trying to hurt the previous posters feelings (6Bra1K) when I stated by all means, if you have the time to do it and it increases your level of confidence on the firing line, then go ahead and do it. And yes, I do believe that your new paint job on your rifle factored into you winning. It increased your confidence and allowed you to focus on your fundamentals and relax.

Dave weighing primer is not a hole im gonna go down, but you gotta admit @Sandstorm John's Mean Green would give ya a certain level of confidence.John cleaned house his 1st match out. Weather it was the primers or paint...
He looked good doing it!!

 

[Dave M.]

Dave weighing primer is not a hole im gonna go down, but you gotta admit @Sandstorm John's Mean Green would give ya a certain level of confidence.View attachment 1324090John cleaned house his 1st match out. Weather it was the primers or paint...
He looked good doing it!!

I couldn’t agree more Brett. I don’t plan to weigh primers any time soon. If you read the article several posts up, it clearly states that in order to likely prove statistically significant, one would have to be accurately measuring primer mass down to 0.1mg (that’s 0.001543 grains). Good luck with that.
dave

 

[JFrank]

For those that do weigh primers, which unit of measure do you prefer
Grams
Grains
I’m leaning towards grams..
Jim

 

[tom]

Grams increases resolution

 

[Dave M.]

According to the data in the Coutney military report referenced above, there may indeed be an advantage present for those that can sort to the quarter or half of a milligram (see source below):


Furthermore, his data shows that the peak blast pressure (psi) vs. primer total mass (mg) regression line has a correlation coefficient (R) for the CCI 450 primers of 0.03, which is ridiculously low and as good as saying there is virtually ZERO correlation between the peak blast pressure and the mass of the CCI 450 primers. So if you are using CCI 450’s, like I am, sorting shows zero benefit.





In any case, I will be sorting primers for my 3x600 F class match next weekend. Typically, in my 600 yard competitions, I’m seeing between .3 to .5 vertical moa (based on measured targets). I’ll report back.
Dave

 

[Rocketvapor]

@Dave M.
Sort until you have an obvious normal distribution of weights.
Take 10 low outliers and 10 high outliers, and the rest from NEAR the mean.
If outliers weighed to the nearest milligram don't show any benefit, weighing to 0.1mg surely won't.
Load your 70 or so rounds for your 600X3 isolating the ten low and 10 high for your second relay.
Ex: Sighters from mean weight, relay one from mean weight, first 10 of relay 2 low outliers, second 10 of relay 2 the high outliers. Shoot relay 3 from the mean weight primers.
All same day, almost the same environment, same reloading batch, same you
Post scores.

One hint for those without a precision lab balance, or just to save a few seconds per primer:
Tare the scale then add a 1 gram check weight to the scale.
Will indicate 1.000g without a primer and 1.350g (or so) with a primer.
Milligram resolution should show outliers. With a milligram indicating scale the +/- half count rollover will be hidden. Range of weight, high to low should be a FEW milligrams. You are only looking for outliers.

With a 1g base, DRIFT and REPEATABILITY will be instantly visible.
Auto zero of balance won't be triggered. At a very small measuring range (light to heavy primer) scale LINEARITY will NOT be a factor. Full scale calibration, percentage based, will NOT be a factor except in the WORST conditions. The 1.000g will monitor every weight performed. If it drifts, remove the check weight, tare, add the check weight.
This 1.000g check weight is a continuous IN PROCESS check.
If you don't trust the process, reweigh the lowest and heaviest outlier after sorting.
Red and green markers in the case groove to track outliers in case you spill the box

 

[Dave M.]

@Dave M.
Sort until you have an obvious normal distribution of weights.
Take 10 low outliers and 10 high outliers, and the rest from NEAR the mean.
If outliers weighed to the nearest milligram don't show any benefit, weighing to 0.1mg surely won't.
Load your 70 or so rounds for your 600X3 isolating the ten low and 10 high for your second relay.
Ex: Sighters from mean weight, relay one from mean weight, first 10 of relay 2 low outliers, second 10 of relay 2 the high outliers. Shoot relay 3 from the mean weight primers.
All same day, almost the same environment, same reloading batch, same you
Post scores.

One hint for those without a precision lab balance, or just to save a few seconds per primer:
Tare the scale then add a 1 gram check weight to the scale.
Will indicate 1.000g without a primer and 1.350g (or so) with a primer.
Milligram resolution should show outliers. With a 1g base, DRIFT and REPEATABILITY will be instantly visible.
Auto zero of balance won't be triggered. At a very small measuring range (light to heavy primer) scale LINEARITY will NOT be a factor. Full scale calibration, percentage based, will NOT be a factor except in the WORST conditions. The 1.000g will monitor every weight performed. If it drifts, remove the check weight, tare, add the check weight.
This 1.000g check weight is a continuous IN PROCESS check.
If you don't trust the process, reweigh the lowest and heaviest outlier after sorting.
Red and green markers in the case groove to track outliers in case you spill the box

I like the process. It is a little different than my process was going to be, but I can certainly see the value in your process. I’ll let you know what happens (if I shoot). My ex has Covid so I’m keeping my son away from her until she is recovered. Hopefully by Saturday next week she will be in the clear (just tested positive this morning).
dave

 

[Rocketvapor]

Wishing you and the Ex the best.

I don't get many opportunities to just test loads @ 600 so I slip in a 10 or 20 round string in the middle of the 60.
I now weight my powder charges in grams with a 10.000g Continuous In process Check weight.