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Garmin Xero and Primer Sorting

Wife and I hit the range in Bogalusa today for some trigger time before the next 600yd match.
She practiced with her Savage 22N bolt gun and I used my 22N AR-15.
Did a small primer sorting test with the AR using velocities from my Garmin.
Scale used for reloading was an A&D EJ54D2 on the low range.

Average primer weight for a hundred primer flat was 3.65 grains.
Loaded up 20 rounds with weight sorted twice fired/annealed brass (22 Nosler/Dogtown), weight and length sorted Berger 85.5 bullets, 31.70 grs of SB6.5, and primers from 3.645 to 3.685 grains (3.65 +/- 0.02 grains)
Found a few light ones at 3.62 to 3.63 grains, and some heavy at 3.73 to 3.75 grains.
Loaded up 5 light and 5 heavy, same brass, bullets, load.

Outlier cases were marked Red and Blue around the primer and shot round robin, one light, one heavy, one light, etc.
Shot a few foulers then Shot 10, then the the outliers, then another ten.

Garmin Xero velocities:
First 10 round middle weight primers, 2993.8 avg.
Light primer avg (5 shots) 2990.3
Heavy primer avg (5 shots) 3018.5
Last 10 round middle weight primers, 2998.7 avg.

The light/ heavy individual velocities:
Light 2989.3
*Heavy 3039.3
*Light 2975.2
Heavy 3007.7
Light 2996.5
Heavy 3018.5
Light 2993.2
Heavy 3011.4
Light 2997.4
Heavy 3015.7
Double checked post for errors. Think I got it right.

AVG for all 30 shots was 2999 including that fast heavy primer 3039.3 and the slow light primer 2975.2.
*Eliminating those two odd ones the 28 shot avg was 2998.4.
 
Last edited:
Here ya go. Ran those numbers out for you.

LightHeavy
2989.3​
3039.9​
Anova: Single Factor
2975.2​
3007.7​
2996.5​
3018.5​
SUMMARY
2993.2​
3011.4​
GroupsCountSumAverageVariance
2997.4​
3015.7​
Column 1
5​
14951.6​
2990.32​
81.567​
Column 2
5​
15093.2​
3018.64​
158.188​
ANOVA
Source of VariationSSdfMSFP-valueF crit
Between Groups
2005.056​
1​
2005.056​
16.72587​
0.003487​
5.317655​
Within Groups
959.02​
8​
119.8775​
Total
2964.076​
9​

A P-value of <0.05 means the two groups of primers are slightly different. In your data, of which there really isn't enough to hang you hat on yet, the P value was 0.003487 so for what little there was we would say those two groups were different statistically.

If you can muster a set of about 30 of the heavy and the light, then you would know for sure, but as it is there is a pretty good chance they will be about a 2" difference at 600 yards on average. Some folks don't care about 2" at 600, some do. YMMV
 
Here ya go. Ran those numbers out for you.

LightHeavy
2989.3​
3039.9​
Anova: Single Factor
2975.2​
3007.7​
2996.5​
3018.5​
SUMMARY
2993.2​
3011.4​
GroupsCountSumAverageVariance
2997.4​
3015.7​
Column 1
5​
14951.6​
2990.32​
81.567​
Column 2
5​
15093.2​
3018.64​
158.188​
ANOVA
Source of VariationSSdfMSFP-valueF crit
Between Groups
2005.056​
1​
2005.056​
16.72587​
0.003487​
5.317655​
Within Groups
959.02​
8​
119.8775​
Total
2964.076​
9​

A P-value of <0.05 means the two groups of primers are slightly different. In your data, of which there really isn't enough to hang you hat on yet, the P value was 0.003487 so for what little there was we would say those two groups were different statistically.

If you can muster a set of about 30 of the heavy and the light, then you would know for sure, but as it is there is a pretty good chance they will be about a 2" difference at 600 yards on average. Some folks don't care about 2" at 600, some do. YMMV
While this test shows some difference, the only way I would conclude anything is if the same test was done again (needing to be repeatable) and showed the same kind of results; just like not looking at and drawing any conclusions based on one or two 5 shot groups kind of thing. Though, I will say, I find the data is interesting. :)
 
I bet you can guess what I'm gonna do for the next match :)
2"@600 is only a part of my groups. I still get some 9's.
I've got plenty more heavy primers out of this brick to try after the match.
The Garmin is going to help. The wife has had this habit of throwing a flyer or two in a 20 round relay.
Today showed velocity was the likely cause (I do the reloading) with her flyers.
Maybe?
But, my goal with the 22N in an AR is to Master Midrange F-Open, and I need everything I can get.
Luck, light Wind, No summer Mirage, Sleep the night berfore, and PRIMERS :)
 
Last edited:
Screen shot from Shot Marker.
Seems to be a bit more than 2" with the 22N and 85.5s

Odd # shots were light primers, even number shots were heavy primers.
From Garmin
Shot 10 Heavy 3015.7 was the highest in elevation but wasn't the fastest.
Probably the shooter, not the Primer.
Shot #2 was faster, 3039.3.
20240307_101603-PRIMER.jpg
 
Last edited:
While this test shows some difference, the only way I would conclude anything is if the same test was done again (needing to be repeatable) and showed the same kind of results; just like not looking at and drawing any conclusions based on one or two 5 shot groups kind of thing. Though, I will say, I find the data is interesting. :)
Yes. Completely correct Straightshooter1.

The speed data is weak with only 5 shots per set, and would need to be on the order of 15 to 30 shots to raise the confidence if that data had to stand alone... but... we don't always need to test if we already know the answer.

The point being, we already know he is doping the test with the primer weights and he has everything else under control and with a good rifle.

When you see more than 0.1 grains difference on primer weights, the answer is a foregone conclusion for someone who can shoot 600 yards like the OP. The variation of primer weights counts for more than the variation of powder weight on a grain for grain basis due to the energy of the compound for cases like the 22N.

When it is a rookie who still can't shoot 95%, I would say there are more important lessons to learn first before you worry about primer sorting, but Rocketvapor has shown that he knows what he is doing so a primer sort will make a difference on his targets.

The only thing we don't know from the small test, is the stats on the primer batch weight variation. It is worth his time to weigh at least 30 or so of those and estimate the batch to evaluate how to bin the sort. I would be happy to crunch the numbers on primer weights if he wants them.
 
Appreciate the kind comments.
Match is on the 16th.
The week or so afterwards I want to test a larger sample. Not only to show difference in heavy vs light but see if a narrow band of weights gets better down range results. Maybe a tight bin of somewhat heavy or light (not the outlying extremes) does better. I will admit the vertical on the light primers is NOT my norm.

I will open a new brick (2022) of CCI450, sort the whole brick, picking out maybe 3.645 to 3.655 grains staying just UNDER whatever the mean is, for the match. That's an indicated range on the scale of 2 counts, plus a count either side for process errors.
I need about 140 for the wife and I. If I can't find enough for the match I'll open another brick. Got a week to get rounds loaded.
Tumbled last night, anneal when it gets dark later on.
After the match I'll work on trigger time rounds.
Then bin light and heavy, keeping track of the severe outliers for my next practice session.
I really need the trigger time to stay up with the wife and her new bolt gun :)
 
Last edited:
Here ya go. Ran those numbers out for you.

LightHeavy
2989.3​
3039.9​
Anova: Single Factor
2975.2​
3007.7​
2996.5​
3018.5​
SUMMARY
2993.2​
3011.4​
GroupsCountSumAverageVariance
2997.4​
3015.7​
Column 1
5​
14951.6​
2990.32​
81.567​
Column 2
5​
15093.2​
3018.64​
158.188​
ANOVA
Source of VariationSSdfMSFP-valueF crit
Between Groups
2005.056​
1​
2005.056​
16.72587​
0.003487​
5.317655​
Within Groups
959.02​
8​
119.8775​
Total
2964.076​
9​

A P-value of <0.05 means the two groups of primers are slightly different. In your data, of which there really isn't enough to hang you hat on yet, the P value was 0.003487 so for what little there was we would say those two groups were different statistically.

If you can muster a set of about 30 of the heavy and the light, then you would know for sure, but as it is there is a pretty good chance they will be about a 2" difference at 600 yards on average. Some folks don't care about 2" at 600, some do. YMMV
I’m willing to do the testing as well if you can send the proper process of firing order and how many of each style need to be fired. I can fire them across a Garmin and all reloading masses would be taken on an A&D Fx120i. Let me how the proper test procedure and I will attempt to follow it to the T.

Dave M
 
I ran them across a Garmin in the order shown.
Each ten shot group (medium weight primers, Light/Heavy primers, medium weight primers) were each shot consecutively with about a minute per shot. 30 shots.
Reloading masses were taken with a EJ-54D2 to a little better than the FX120I can do.
:)

Next test I will record the individual primer weight for each shot.
Smaller cases will probably show larger differences in velocity/primer weight than big cases. 223/5.56 would likely show more variance. But I'll be shooting 22N.
 
Last edited:
Sorted the remainder of the previous brick. There will be some overlap in the groups.
I need a few more of the 3.64gr group to make a batch for Saturday's match.
Might fudge some lighter ones from the 3.66 group.
Have enough of the 3.66, 3.68, and 3.70gr
Range of what I got was 3.615gr to 3.755gr.Then next week Highs and Lows.
Another-Primer-Sort.jpg
 
Sorted the remainder of the previous brick. There will be some overlap in the groups.
I need a few more of the 3.64gr group to make a batch for Saturday's match.
Might fudge some lighter ones from the 3.66 group.
Have enough of the 3.66, 3.68, and 3.70gr
Range of what I got was 3.615gr to 3.755gr.Then next week Highs and Lows.
View attachment 1534956
Rather than using the cup to sort them, may I suggest to set each one on the scale individually with some long shop tweezers. I think it is faster and then I remove it from the scale and place it into a plastic container of the proper weight. I don’t do this all the time but I’ve done it three times to run experiments and found this method to be the quickest.
Dave
 
Made it to the match and I got wupped :(
Wife started out with a cold bore X and started score.
Then went into this adjust scope up, no, adjust scope the other up, then finally got on track.
She got 192-2X, 196-7X, 197-9X 97.5%
ME 195-3X, 190-7X, 189-5X 95.67%

I screwed up and ran the whole string, 134 shots on the Garmin and when I got home data past 100 is gone.

Flo-1
Max 3009.2 Min 2958.9 Mean 2978-7 ES 49.3
On line calculator SD 15.6

RV-1
MAX 3022.2 MIN 2951.5 Mean 2981.3 ES 70.7
SD 18.57

Flo-2
MAX 3008.1 MIN 2956.7 MEAN 2981.9 ES 51.4
SD 12.92

RV-2
MAX 3003.3 MIN 2955.4 MEAN 2977.8 ES 47.9
SD 14.54

Flo-3 Data Lost, I took a screen shot since it was her all time high, from Shotmarker
AVG 2060 SD 20.6 SCORE 197-9X

RV-3 Data Lost
 
Last edited:
197-9X is HM territory and pretty darned good! Congrats to Flo!
Bummer about the lost data.
How was your vertical?
Glad you two got out to shoot the match.
 
Some of my 9's were vertical but the 8's were wind.
(appropriate use of an excuse :) )
This trip was with 30.7gr SB6.5. Velocities dropped a little and groups might have opened up a tad.
Going back to 30.8gr
 
Last edited:
Changed springs in Flo's Savage.
Hope it's not too light for her.

Got some more Win41 primers and will let her try the 41's (20ea) and CCI450 (20ea) plus some foulers.
Didn't do a deep clean on the barrel.
Played with the springs and got a 7oz pull with about 50% blade force.
Original Trigger and Sear.
10 pull average is 7.2oz, range was 7.4 to 6.8

I sorted and loaded some Light-Heavy CCI450 for another primer weight test for me to shoot in the AR.
Recorded individual weights and will shoot 6 groups of 5. I should be able to correlate weight to Garmin to ShotMarker.
Need to figure out how to get the whole group to show on the ShotMarker.
Sometimes it only shows last shot, sometimes the whole group.
7oz-trigger.jpg
 
Last edited:
Rather than using the cup to sort them, may I suggest to set each one on the scale individually with some long shop tweezers. I think it is faster and then I remove it from the scale and place it into a plastic container of the proper weight. I don’t do this all the time but I’ve done it three times to run experiments and found this method to be the quickest.
Dave
I do the same, long pickups without teeth, makes it very fast to sort and you don’t have to tough the primers if that matters.
 

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