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Primer Sorting for Precision Loads

GunnyUSMC

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Nov 24, 2022
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Does anyone sort their primers based on Primer Height?

I have sorted my primers based on weight but that was more to identify outliers than actually sorting by weight.

Recently, i have become much more aware of the importance of consistent primer seating and have learned along the way how difficult this can be because the primers themselves often deviate in height up to .003. That deviation will have a major effect on the desired primer seating depth.

Just wondering if anyone else is concerned with or have encountered similar primer related challenges and what they have done to address it.
 
Gunny, some primers are designed where the anvil "sticks up" and some are designed with the anvil flush to the cup.

The ones with the anvils that stick up, are intended to be "consolidated" (or what the forum calls "crush"). That variation you are seeing means you are going to have to take an average height dimension and make sure the shortest and longest ones are not rejects. Then your seating depth needs to have an average "crush" of 0.004" to 0.006" to make it a non issue.

Primers seated within a window of that consolidation will not cause a performance problem, but if you were in a lab with a dedicated test rig, you could easily show that if primers are not at least "consolidated" or when they are pushed in so deep that they are damaged, we can demonstrate problems. The takeaway is, by getting the anvil pressed into the cup at least several thousandths, the performance is not affected within a practical window, but if you under or over crush them by going outside of that window, you will get issues.

I am not sure if what you are calling deviation means you got a total range of 0.003" or if that means you got a plus and minus of 0.003" which is a range of 0.006". I am hoping it means you got a total range of 0.003" in which case you assemble with your average height and carry on.

I will just add some food for thought for the folks who don't observe any MV correlation with primer weight.

Consider the primer charge as what it would be in equivalent powder grains. Many folks cannot shoot or measure the difference of their powder charges due to the concept of that parameter being in a composite summation of many other variables that puts it in the noise.

When a system is very tight, variations in powder or primer weights show up. When a system is noisy, they cannot. Sometimes, a tight system doesn't show any issue with primer weight variation, because the weight variation is small. If you gave that person the high and low primers from a different batch, they would see the difference. The point being, it is difficult to judge how much weight variation we are discussing, and it is made more difficult when the resolution of the system is lower due to ignition issues, brass prep issues, or ignition issues.

If you didn't see a MV stat change due to weight variation in a primer, then it one of two reasons, low resolution or really good primers. Carry on, YMMV
 
Does anyone sort their primers based on Primer Height?

I have sorted my primers based on weight but that was more to identify outliers than actually sorting by weight.

Recently, i have become much more aware of the importance of consistent primer seating and have learned along the way how difficult this can be because the primers themselves often deviate in height up to .003. That deviation will have a major effect on the desired primer seating depth.

Just wondering if anyone else is concerned with or have encountered similar primer related challenges and what they have done to address it.
I take measurements of the primer heights (only a sample size of ~10, so not all of them) and right the range on the packet of 100, which is typically in a range of .002 to .0025. I also uniform my primer pockets and know the depth of the pockets so I know how deep to see the primers in the particular brass I'm using (different brass having different pocket depths).

Being that all the primers I use (CCI, Federals and Remington's) have the anvil well above the actual cup, I'll seat the primers to the shortest height to touch the bottom of the pockets. With the variation in primer height and being that close to the bottom of the pockets doesn't produce any measurable difference in velocity. You just don't want the bottom of the primers to be far from the bottom of the pockets. Too far from the bottom will produce inconsistent ignition . . . just as too much "crush" will too.
 
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The ones with the anvils that stick up, are intended to be "consolidated" (or what the forum calls "crush"). That variation you are seeing means you are going to have to take an average height dimension and make sure the shortest and longest ones are not rejects. Then your seating depth needs to have an average "crush" of 0.004" to 0.006" to make it a non issue.
so allow me to expand a little on what i am attempting to accomplish… and why

I shoot F-TR with a .223Rem. I have been able to develop a really good load that allows me to shoot in the mid 590s out of 600 possible points at 800yds with 25 out of 60 shots in the X ring. The net result is probably about a .75MOA group at 800yds.

I have never really paid great attention (some attention but not a major focus) to primer seating depths. Now i am looking for that last little bit that can make the difference between winning and not-winning a match. My last match i shot a 594 and missed the win due to a primer related issue pushing my shot into the 9 ring.

I have a decent understanding of primers/cups/anvils/pockets and how they work together. I have used a few different primer seating tools from cheap to expensive (I am now using the Primal Rights CPS) and with all of them, I have struggled to get all my primers seated to the same depth. My primer of choice for my .223 is the BR4 and my desired seating depth for the primers (based on calculations of primer pocket depth and primer height) is .003. However, i keep coming up with small numbers of primers that will just not seat beyond .001 and havent figured out why.

I have always sorted primers by weight but lately i decided to start sorting by primer height thinking that is what is causing my inconsistency issue. To that end, I have seen primer heights ranging from .1195 - .125, a spread of .0055. Most of my primers are between .120 and .121 with a handful coming in at .122 and .123 and, of course, that .125. While i do not have full confidence in these numbers, I am working on a plan to have more confidence in the results of my measurements and the experience so far has at least let me know that even the BR4 will have significant variations in primer height.

my plan is to first figure out how to effectively and efficiently measure my primer heights and then seat my primers to a depth based on the different heights.

measuring the height of those little primers is a PIA and I keep hoping there is a cool little tool out there that will make the process a little easier.
 
Now i am looking for that last little bit that can make the difference between winning and not-winning a match. My last match i shot a 594 and missed the win due to a primer related issue pushing my shot into the 9 ring.

I'm curious - how you were able to determine it was a primer issue?
 
so allow me to expand a little on what i am attempting to accomplish… and why

I shoot F-TR with a .223Rem. I have been able to develop a really good load that allows me to shoot in the mid 590s out of 600 possible points at 800yds with 25 out of 60 shots in the X ring. The net result is probably about a .75MOA group at 800yds.

I have never really paid great attention (some attention but not a major focus) to primer seating depths. Now i am looking for that last little bit that can make the difference between winning and not-winning a match. My last match i shot a 594 and missed the win due to a primer related issue pushing my shot into the 9 ring.

I have a decent understanding of primers/cups/anvils/pockets and how they work together. I have used a few different primer seating tools from cheap to expensive (I am now using the Primal Rights CPS) and with all of them, I have struggled to get all my primers seated to the same depth. My primer of choice for my .223 is the BR4 and my desired seating depth for the primers (based on calculations of primer pocket depth and primer height) is .003. However, i keep coming up with small numbers of primers that will just not seat beyond .001 and havent figured out why.

I have always sorted primers by weight but lately i decided to start sorting by primer height thinking that is what is causing my inconsistency issue. To that end, I have seen primer heights ranging from .1195 - .125, a spread of .0055. Most of my primers are between .120 and .121 with a handful coming in at .122 and .123 and, of course, that .125. While i do not have full confidence in these numbers, I am working on a plan to have more confidence in the results of my measurements and the experience so far has at least let me know that even the BR4 will have significant variations in primer height.

my plan is to first figure out how to effectively and efficiently measure my primer heights and then seat my primers to a depth based on the different heights.

measuring the height of those little primers is a PIA and I keep hoping there is a cool little tool out there that will make the process a little easier.
shot a fair amount of f-class. your 9 is unlikely to be a primer issue. I would try different primers over primer sorting - cci450 gave me the best results. Trying different primers will yield more result than sorting.
 
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Like @Supersubes said I have done every thing you can think of when it comes to brass, bullet and load prep and have tested all at 1000yds 1 step at a time(I literally live 10mins from where I can shoot miles)and I can tell you this....one or two thing do not make a difference and everything did not make a big enough difference for me to pursue any of it.

I know 5 shot groups do not matter but both these groups are the same 6BRA on the same day, top is 109hybrids bottom is 105 hybrids, the 3 chrony pics are the same day and all 40 rounds are the 105 hybrid load...now here's the hard part to swallow, I load on a Dillon 750.
 

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Like @Supersubes said I have done every thing you can think of when it comes to brass, bullet and load prep and have tested all at 1000yds 1 step at a time(I literally live 10mins from where I can shoot miles)and I can tell you this....one or two thing do not make a difference and everything did not make a big enough difference for me to pursue any of it.

I know 5 shot groups do not matter but both these groups are the same 6BRA on the same day, top is 109hybrids bottom is 105 hybrids, the 3 chrony pics are the same day and all 40 rounds are the 105 hybrid load...now here's the hard part to swallow, I load on a Dillon 750.
I have a buddy shooting f-class competitively nationally who loads on the 750. F class john also loads on one. I am too invested in my 419 and not shooting enough to justify the switch but it's pretty incredible the ammo that can come off those.
 
I have a buddy shooting f-class competitively nationally who loads on the 750. F class john also loads on one. I am too invested in my 419 and not shooting enough to justify the switch but it's pretty incredible the ammo that can come off those.
I do not like reloading, I burnt myself out playing with all the things I mentioned above for several years. I actually stopped shooting for several months because I hated all the prep work and that’s when I stopped all the nonsense and bought a 750…I still do not like reloading but it’s a necessary evil and the 750 makes it tolerable.
 
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I do not like reloading, I burnt myself out playing with all the things I mentioned above for several years. I actually stopped shooting for several months because I hated all the prep work and that’s when I stopped all the nonsense and bought a 750…I still do not like reloading but it’s a necessary evil and the 750 makes it tolerable.
I used to reload to shoot, now sometimes I think I shoot to reload. I appreciated the precision of it when my shooting volume declined once I wasn't shooting competitive F-Class. Now I only reload a little over 2k rounds a year. Nice tools helped my enjoyment a lot - giraud, amp + amp mate, sac dies, etc
 
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I'm curious - how you were able to determine it was a primer issue?
Well, it is not for the same reasons I started this thread but it was the last straw that told me i need to pay more attention to my primers...

I had a blown primer. I mean the primer blew completely out of the primer pocket. It wasnt due to pressure but instead to a loose primer pocket. I am a little embarrassed but i recognized the potential issue during the priming process and even marked the case head with a red marker. Somehow, that case still made it into my match loads.
 
I do not like reloading, I burnt myself out playing with all the things I mentioned above for several years. I actually stopped shooting for several months because I hated all the prep work and that’s when I stopped all the nonsense and bought a 750…I still do not like reloading but it’s a necessary evil and the 750 makes it tolerable.

well, i am quite the opposite. no phone, no music, no noise at all other than my equipment at each stage of case prep and loading. I get up a 5:30am and head to the gun room for about 2 hours to get my day started right. I love the challenge in making the best precision loads possible, not there yet. I manage .223 for my F-TR, .308 for my daughter’s F-TR, .308 for my M14 M21, .338 Edge for ELR and am now getting into F-Class Rimfire with my Anschutz (though you cannot reload these). I spend my days testing different powder weights for my M14 to get the 175gr SMK to go at 2550mv so it works with my antique ART II scope and testing different bullet seat depths as part of ongoing tuning process for F-TR. It is like a ongoing science project.

Yea…. I love it. It keeps me sane and grounded.
 
so allow me to expand a little on what i am attempting to accomplish… and why

I shoot F-TR with a .223Rem. I have been able to develop a really good load that allows me to shoot in the mid 590s out of 600 possible points at 800yds with 25 out of 60 shots in the X ring. The net result is probably about a .75MOA group at 800yds.

I have never really paid great attention (some attention but not a major focus) to primer seating depths. Now i am looking for that last little bit that can make the difference between winning and not-winning a match. My last match i shot a 594 and missed the win due to a primer related issue pushing my shot into the 9 ring.

I have a decent understanding of primers/cups/anvils/pockets and how they work together. I have used a few different primer seating tools from cheap to expensive (I am now using the Primal Rights CPS) and with all of them, I have struggled to get all my primers seated to the same depth. My primer of choice for my .223 is the BR4 and my desired seating depth for the primers (based on calculations of primer pocket depth and primer height) is .003. However, i keep coming up with small numbers of primers that will just not seat beyond .001 and havent figured out why.

I have always sorted primers by weight but lately i decided to start sorting by primer height thinking that is what is causing my inconsistency issue. To that end, I have seen primer heights ranging from .1195 - .125, a spread of .0055. Most of my primers are between .120 and .121 with a handful coming in at .122 and .123 and, of course, that .125. While i do not have full confidence in these numbers, I am working on a plan to have more confidence in the results of my measurements and the experience so far has at least let me know that even the BR4 will have significant variations in primer height.

my plan is to first figure out how to effectively and efficiently measure my primer heights and then seat my primers to a depth based on the different heights.

measuring the height of those little primers is a PIA and I keep hoping there is a cool little tool out there that will make the process a little easier.
Yeah, measuring the heights are definitely a PIA, and likewise I'd sure be interested in finding an easy button to do it. In the meantime, I just use a caliper (my dexterity is still good enough at my advance age, fortunately ;)).

If you haven't already seen this video, maybe you'll find it of some interest:
 
so allow me to expand a little on what i am attempting to accomplish… and why

I shoot F-TR with a .223Rem. I have been able to develop a really good load that allows me to shoot in the mid 590s out of 600 possible points at 800yds with 25 out of 60 shots in the X ring. The net result is probably about a .75MOA group at 800yds.

I have never really paid great attention (some attention but not a major focus) to primer seating depths. Now i am looking for that last little bit that can make the difference between winning and not-winning a match. My last match i shot a 594 and missed the win due to a primer related issue pushing my shot into the 9 ring.

I have a decent understanding of primers/cups/anvils/pockets and how they work together. I have used a few different primer seating tools from cheap to expensive (I am now using the Primal Rights CPS) and with all of them, I have struggled to get all my primers seated to the same depth. My primer of choice for my .223 is the BR4 and my desired seating depth for the primers (based on calculations of primer pocket depth and primer height) is .003. However, i keep coming up with small numbers of primers that will just not seat beyond .001 and havent figured out why.

I have always sorted primers by weight but lately i decided to start sorting by primer height thinking that is what is causing my inconsistency issue. To that end, I have seen primer heights ranging from .1195 - .125, a spread of .0055. Most of my primers are between .120 and .121 with a handful coming in at .122 and .123 and, of course, that .125. While i do not have full confidence in these numbers, I am working on a plan to have more confidence in the results of my measurements and the experience so far has at least let me know that even the BR4 will have significant variations in primer height.

my plan is to first figure out how to effectively and efficiently measure my primer heights and then seat my primers to a depth based on the different heights.

measuring the height of those little primers is a PIA and I keep hoping there is a cool little tool out there that will make the process a little easier.
Some of the problem, is the seaters that run and add the rim thickness problem to the rest of the parameters you are adding up to get to your assembly.

I would worry a little less about those total primer heights, and pay attention to the weights and finished seated depths.

It also goes without saying the rest of the brass prep and pocket depths need to be on point too.

I am sure at this point, you get the picture that the ignition needs to be maintained to keep it from being a problem, especially once we get past 600 yards, and we make it more challenging by running 223... but I got faith in you. Good Luck and in for the range reports.
Semper Fi
 
but it's pretty incredible the ammo that can come off those.
Yes, but keep in mind that some of the top flight shooters may also be augmenting the 750 with some tricks that are not typical.

For example, there are priming modifications, as well as externally measured charges that can be dropped into a funnel at the charge station, that can greatly enhance the results of the 750.
 
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For .223 i run BR4 primers and for .308 F-TR, i run the CCI450 primers with Palma brass. I had a batch of 153 CCI450 primers that i had already sorted by weight and figured out a way to effectively measure primer height. The results were as follows:

88 at .121
34 at .120
16 at .122
10 at .119
4 at .123
1 at .125

I used the Precision Primer Gauge (by bullettipping.com) and zeroed it for measuring ,223 Rem primer pockets. I then turned the gauge upside down, placed a primer on the measuring pin and then compressed it with the provided zero gauge/tool. This worked pretty well and results were pretty consistent. It was not super fast but I was able to get through all the primers in approximately 30min.

For the next step in this exercise, i will verify primer pocket depth for my brass and then set my CPS to seat primers of the same height (.121) to .004. It will be interesting to see if I experience any of the same issues as before.

Following this, i will complete my loads and head to the range to see if i notice any improvement in SD and ES.
 
For .223 i run BR4 primers and for .308 F-TR, i run the CCI450 primers with Palma brass. I had a batch of 153 CCI450 primers that i had already sorted by weight and figured out a way to effectively measure primer height. The results were as follows:

88 at .121
34 at .120
16 at .122
10 at .119
4 at .123
1 at .125

I used the Precision Primer Gauge (by bullettipping.com) and zeroed it for measuring ,223 Rem primer pockets. I then turned the gauge upside down, placed a primer on the measuring pin and then compressed it with the provided zero gauge/tool. This worked pretty well and results were pretty consistent. It was not super fast but I was able to get through all the primers in approximately 30min.

For the next step in this exercise, i will verify primer pocket depth for my brass and then set my CPS to seat primers of the same height (.121) to .004. It will be interesting to see if I experience any of the same issues as before.

Following this, i will complete my loads and head to the range to see if i notice any improvement in SD and ES.

What are your current es/sd numbers?How much improvement will you need to see to justify the effort it took to get there?
 
Today, my SD is around 7-8 and ES around 17-20. I would love to get my ES in the single digits but if I can get it consistently between 10-15, I will be happy with that.