Rifle Brass Sorting Experiment - Part Two: Microstamping

[ammolytics]

Hey SH!

I published the second article in my series about sorting rifle brass. In this installment, I explain how I microstamped my brass to keep track of it over its lifespan, even through 24 hours of tumbling with stainless media. This method allows you to sort once by weight or other method and keep it sorted, so that you can track per-case performance data instead of randomizing each time you reload.

https://blog.ammolytics.com/2020-06-07/brass-sorting-part-two.html

As always, I hope that it's high quality enough to justify the time you spend reading it, and how much time it took me to create it.

I'd love to hear your feedback and answer any questions!

-Eric @ Ammolytics

 

[NH4X]

Interesting..................very interesting, as is part 1. Thx for sharing.

 

[918v]

You’re not going to appreciate my feedback.

I think that using common sense and a practical approach to organizing your brass inventory is better to stamping. You don’t have to buy any tools. You don’t have to spend the time stamping the brass.

Plastic bags, sharpie, brain...

 

[ammolytics]

You’re not going to appreciate my feedback.

I think that using common sense and a practical approach to organizing your brass inventory is better to stamping. You don’t have to buy any tools. You don’t have to spend the time stamping the brass.

Plastic bags, sharpie, brain...

I understand that it's not for everyone. I explained the problem that I had and why I felt this was a good solution, as well as the pros/cons. I'm not selling anything here, just sharing what I learned along the way.

For what it's worth, one local competitive marksman (F-Class, on Lapua's team) has been collaborating with me on this and in his own dataset (30 cases, fired 5x times) we found ~ 8 cases which were consistently <= 15ft/s and others which were > 30 ft/s.

As I wrote, more data is needed for this approach and it's targeted more towards competitors looking for an edge.

 

[918v]

But then you also dont know. Thats not very scientific and exactly the reason why he is stamping.


In this case writing it down into the brass.

Don’t know what?

 

[918v]

What the fuck are you talking about? Individual piece? Are you suggesting that microstamping is the only way to make sure you don’t mix brass?

 

[918v]

How am I being an ass? Because I disagree with the notion that one needs to buy additional tools and waste time punching numbers into the case head when the same thing can be accomplished with a sharpie marker? What, am I required to prostrate myself before everyone who comes up with something new? I’m not an ass in every thread. You are a liar.

 

[30cal user]

918, if you were clean the brass and remove the sharpie....this solution takes care of that, this is free information, its interesting that he does this for free, saves us a lot of time.....


ammolytics please keep going

 

[918v]

918, if you were clean the brass and remove the sharpie....this solution takes care of that, this is free information, its interesting that he does this for free, saves us a lot of time.....


ammolytics please keep going

Sharpie survives loading, firing, and storage. Put the spent brass in a plastic bag. That sharpie will remain readable until you’re ready to clean and reload it. Then you can mark it again. At least the new mark will be valid, unlike the stamp.

 

[918v]

You don’t fucking get it. When you take the brass out of the tumbler you size it and then put a new mark on it. Or put it in a bag and bark the bag. It’s pretty straight forward.

 

[918v]

How do you track individual cases? By not mixing them with other cases.

 

[ammolytics]

Hey folks, it's not worth arguing over on the internet.

There's probably a disconnect here about goals.

If your goal is to keep your brass sorted by batch/lot/group, then microstamping is overkill.

However, my goal is to track individual pieces of brass (case # 1-100, not batches) in a way that would not be lost after wet tumbling with ss media. Tumbling is like those lottery ball machines -- it randomizes things again.
My goal is to record per-case measurements like velocity, pressure, length, depth, weight, and volume -- and record them over the lifespan of the brass.
I'm doing this because my goal is to learn why some cases perform better than others.

My goal may not be your goal, and that's OK!
I'm not telling anyone that they should do this, I'm explaining why I'm doing it and what I learned by doing so.

 

[spife7980]

How do you track individual cases? By not mixing them with other cases.

 

[Gunfighter14e2]

Wish I could read the wind at distance where the slightest difference in the brass made a difference on target for that first rd. Then again I don't care for group shooting with wind flags an spotting rds. All I'm looking for is, am I getting better or worst with that first rd on out there.

 

[918v]

 

[30cal user]

You don’t fucking get it. When you take the brass out of the tumbler you size it and then put a new mark on it. Or put it in a bag and bark the bag. It’s pretty straight forward.

you really need to calm down, he wants to keep track of every single case individually.....eliminate the flyers/vertical

 

[ammolytics]

Have you tried a micro engraver? Stamping them would take alot of time.

I was able to stamp 250 cases in about an hour with the drill press jig I used. Not terrible, but it wasn't expensive either. The first phase of any prototypical process are usually manual and slow -- it's not worth automating until you're certain that it needs to be done at a larger scale.

Wish I could read the wind at distance where the slightest difference in the brass made a difference on target for that first rd. Then again I don't care for group shooting with wind flags an spotting rds. All I'm looking for is, am I getting better or worst with that first rd on out there.

My work is about reducing ammunition performance uncertainty. To that end and with the process I've written about here, I've already seen evidence that there's a measurable effect from case to case. This chart, for example, uses data from a fellow competitive F-Class shooter on the Lapua team. It represents 30 cases (10 "light", 10 "heavy", 10 control/median). He fired each of them 5 times.

Cases 5, 6, 8, 10, 11, 18, 19, C2, C4, C5 all have a velocity spread <= 15 ft/s
Cases 1, 13, 14, C10 all have a velocity spread > 30 ft/s
That's a lot of variability that you can remove to reduce uncertainty and focus on your wind calls instead.

Note: I also have trend lines in this chart to show the velocity increase as the barrel warms up. You'll note that the muzzle_5 group shows a backward trend. That's because he shot that group in a different order for that string -- from least capacity to most.

 

[918v]

you really need to calm down, he wants to keep track of every single case individually.....eliminate the flyers/vertical

I’m perfectly calm.

 

[spife7980]

 

[Gunfighter14e2]

I was able to stamp 250 cases in about an hour with the drill press jig I used. Not terrible, but it wasn't expensive either. The first phase of any prototypical process are usually manual and slow -- it's not worth automating until you're certain that it needs to be done at a larger scale.




My work is about reducing ammunition performance uncertainty. To that end and with the process I've written about here, I've already seen evidence that there's a measurable effect from case to case. This chart, for example, uses data from a fellow competitive F-Class shooter on the Lapua team. It represents 30 cases (10 "light", 10 "heavy", 10 control/median). He fired each of them 5 times.

Cases 5, 6, 8, 10, 11, 18, 19, C2, C4, C5 all have a velocity spread <= 15 ft/s
Cases 1, 13, 14, C10 all have a velocity spread > 30 ft/s
That's a lot of variability that you can remove to reduce uncertainty and focus on your wind calls instead.

Note: I also have trend lines in this chart to show the velocity increase as the barrel warms up. You'll note that the muzzle_5 group shows a backward trend. That's because he shot that group in a different order for that string -- from least capacity to most.

View attachment 7349310

Laughing,...

 

[30cal user]

I was able to stamp 250 cases in about an hour with the drill press jig I used. Not terrible, but it wasn't expensive either. The first phase of any prototypical process are usually manual and slow -- it's not worth automating until you're certain that it needs to be done at a larger scale.




My work is about reducing ammunition performance uncertainty. To that end and with the process I've written about here, I've already seen evidence that there's a measurable effect from case to case. This chart, for example, uses data from a fellow competitive F-Class shooter on the Lapua team. It represents 30 cases (10 "light", 10 "heavy", 10 control/median). He fired each of them 5 times.

Cases 5, 6, 8, 10, 11, 18, 19, C2, C4, C5 all have a velocity spread <= 15 ft/s
Cases 1, 13, 14, C10 all have a velocity spread > 30 ft/s
That's a lot of variability that you can remove to reduce uncertainty and focus on your wind calls instead.

Note: I also have trend lines in this chart to show the velocity increase as the barrel warms up. You'll note that the muzzle_5 group shows a backward trend. That's because he shot that group in a different order for that string -- from least capacity to most.

View attachment 7349310

is next step to test H20 capacity of each case before and after firing and through out life cycle to see if this gives any more answers?

 

[Dschapp44]

I was able to stamp 250 cases in about an hour with the drill press jig I used. Not terrible, but it wasn't expensive either. The first phase of any prototypical process are usually manual and slow -- it's not worth automating until you're certain that it needs to be done at a larger scale.




My work is about reducing ammunition performance uncertainty. To that end and with the process I've written about here, I've already seen evidence that there's a measurable effect from case to case. This chart, for example, uses data from a fellow competitive F-Class shooter on the Lapua team. It represents 30 cases (10 "light", 10 "heavy", 10 control/median). He fired each of them 5 times.

Cases 5, 6, 8, 10, 11, 18, 19, C2, C4, C5 all have a velocity spread <= 15 ft/s
Cases 1, 13, 14, C10 all have a velocity spread > 30 ft/s
That's a lot of variability that you can remove to reduce uncertainty and focus on your wind calls instead.

Note: I also have trend lines in this chart to show the velocity increase as the barrel warms up. You'll note that the muzzle_5 group shows a backward trend. That's because he shot that group in a different order for that string -- from least capacity to most.

View attachment 7349310

Thanks for sharing the results. While this is a little beyond what I plan on doing, it's always nice to learn more and I think that tracking the data in this way removes any guess work regarding which case is which. Curious to see what else comes out of this.

 

[ammolytics]

is next step to test H20 capacity of each case before and after firing and through out life cycle to see if this gives any more answers?

Case volume, among other things, will be measured -- yes!