Rifle Brass Sorting Experiment - Part One

[BartsBullets]

All of the sorting brass by Weight, Water-boarding (H2O capacity) , measuring the web is just a guess of what velocity the case will produce.

Personally, I sort my brass by weight, (100 at a time) match them as closely as possible. Then I load them as perfectly as I can and then run them over a chronograph (usually a Magneto speed and Labradar at the same time) Anything other than actually testing and recording the velocity of each case is an educated guess. It might be a very good educated guess, but still a guess.

Bart

 

[Ned Ludd]

Case volume is merely one variable out of many that as reloaders we try to control. However, uniform case volume does not guarantee uniform velocity, regardless of whether you sorted the cases by weight, or measured internal volume with water. The physics and geometry that strongly support the notion that case weight can be used as a surrogate for case volume are quite simple and completely valid. I understand and therefore accept and trust the science behind that idea. For that reason, I don't need to determine water volume for every single case. That's the whole point of using science as the basis to facilitate and expedite the reloading process. For those that disagree, that's fine, and the remedy is to accurately measure the water volume of every single case you use. Both approaches can work, one simply takes a substantial amount more time and effort than the other.

The bottom line is that neither approach for estimating or determining case volume is a guarantee of what velocity that case will actually produce. Why? Because consistent case volume is not the only variable that goes into generating uniform velocity. Precise charge weight delivery, uniform neck tension, and uniform primer brisance are also critical for uniform velocity. As noted in the post above, Bart has addressed this issue by adding a velocity determination step as part of his brass prep process, which is a pretty smart idea, and clearly has worked out ridiculously well for him. However, even that approach is arguably not "perfect". You can only fire a loaded piece of brass and measure velocity once before the case must be re-prepped and there is no guarantee that every case will produce uniform velocity on subsequent firings, even if most of them do. Further, using that approach will require additional effort in the form of sorting and or culling. So this approach has demonstrably worked outstandingly well for Bart, but may not be the "perfect" approach" for everyone.

The point I'm trying to make is that there really are no "perfect" approaches. There will never be any "perfect" approaches. Each approach will have merits and liabilities, meaning that the choice between approaches is largely personal and must be made with some understanding of the process involved. For that reason, it is far more important IMO, for reloaders to have some grasp of the the factors that contribute to variance, whether it be velocity variance, seating depth variance, or any other type of variance they might encounter. If there is some understanding of a process, then informed choices can be made to deal with any inconsistencies that arise during that process, regardless of what those choices are. In other words, there is no right or wrong answer regarding how to best sort brass. There is only information and personal preference. My suggestion would be to pick a method, any method you like, and then test it. Determine for yourself whether it makes a difference on the target or scoreboard that you can actually quantify. If it works, you can incorporate it into your workflow. If not, you can try something else. Actual testing and rigorous quantification are how reloaders push the envelope to improve and refine their methods.

 

[BartsBullets]

As noted in the post above, Bart has addressed this issue by adding a velocity determination step as part of his brass prep process, which is a pretty smart idea, and clearly has worked out ridiculously well for him. However, even that approach is arguably not "perfect". You can only fire a loaded piece of brass and measure velocity once before the case must be re-prepped and there is no guarantee that every case will produce uniform velocity on subsequent firings, even if most of them do. Further, using that approach will require additional effort in the form of sorting and or culling. So this approach has demonstrably worked outstandingly well for Bart, but may not be the "perfect" approach" for everyone.

Ned

Got to call you on that one buddy.

For a competitive shooter I can’t think of a better or more accurate way to test or quantify brass. The results are repeatable. I’ve proven it time after time over the past three years. Remember I’m the guy running a chronograph not only tuning and practicing, but also durning matches. My brass get tested time and time again over the course of their lives. So I know it’s very repeatable.

Can someone tell me a better way to sort or test brass. One That provides real world, repeatable results. When I’m done testing there are No surprises, No outliers that’s what matters.

Bart

 

[Ned Ludd]

Ned

Got to call you on that one buddy.

For a competitive shooter I can’t think of a better or more accurate way to test or quantify brass. The results are repeatable. I’ve proven it time after time over the past three years. Remember I’m the guy running a chronograph not only tuning and practicing, but also durning matches. My brass get tested time and time again over the course of their lives. So I know it’s very repeatable.

Can someone tell me a better way to sort or test brass. One That provides real world, repeatable results. When I’m done testing there are No surprises, No outliers that’s what matters.

Bart

Bart, I think you're misinterpreting the intent of my message. I should have added that as a place to start, your method for sorting brass is likely the best and most complete approach I have ever seen posted. In fact, I was concerned my reference to your method might seem a little negative and was going to do so, but I walked outside as I was thinking about it and you responded before I had a chance to edit the original. So I'll add here that I was in no way intending to denigrate your method whatsoever. In fact, I would argue that your success strongly supports the validity of your approach, and anyone contemplating adding a brass sorting method should consider adopting it. As you noted, anyone that disagrees with that statement need only look at your results. Nonetheless, I think you'll agree that no sorting method known to man is "perfect". If there were such a thing, we'd all be shooting strings with zero ES/SD and groups that were all one hole. I am fully aware your results are getting frighteningly close to that standard . Nonetheless, it is possible that there still may be room for some very, very minor improvement before shooters are routinely placing all their shots in a single hole at 600 to 1000 yd.

The good news for most of us is that sorting methods don't have to be "perfect". Any chosen method need only be an improvement, not perfect. My point is that it's easy for someone with a little knowledge to point out potential flaws in pretty much any known method. What's more important is to pick a method and test it yourself, as you have done. The results of such testing are an important factor, together with the amount of effort involved, for deciding on the best approach to use for a given shooting application. Again, sorry about suggesting I have a negative impression of your method, it really wasn't intended that way. I was merely using your approach as a model to highlight the notion that even the very best approaches out there may not yet be perfect, but that picking a method and testing it in their own hands is the most reliable way for shooters to determine for themselves what is optimal for their own application.

 

[memilanuk]

Bart,

For the sake of argument/discussion, what kind of consistency do you see when testing brass by velocity? Over how many firings?

I'm curious, because it sounds a bit like a method I heard about early on when I was just starting out in the LR F-class game... where the guy I heard it from was firing every piece of brass over a 35P chrono twice, writing the velocity on the brass each time. Only kept the ones that had an ES of 0. Given the amount of brass involved (2k piece lots), the caliber (6.5-06 Imp) and the instrumental accuracy of scales and chronos available at the time (this was 12-15 years ago)... I had a very hard time believing that even consigning a barrel to its fate as a test platform would result in anything approaching repeatable velocity results over 4000 rds of 6.5-06 AI. The very few other people I ever encountered that tried replicating the process had minimal success.

Seems like you're having pretty good results with your approach, so I'm curious as to the particulars of how you do that portion of it (testing/sorting brass). Is it really just that - take prepped brass with a known-good load in a test barrel (old shot-out one, or new one that is a 'duplicate' of your match barrel, or your actual match tube?) and chrono'ing every single round, and keeping the most consistent for use in 'big' matches? Or is there something else to it - assuming that wouldn't involve spilling the magic beans

Monte

 

[BartsBullets]

Bart,

For the sake of argument/discussion, what kind of consistency do you see when testing brass by velocity? Over how many firings?

I'm curious, because it sounds a bit like a method I heard about early on when I was just starting out in the LR F-class game... where the guy I heard it from was firing every piece of brass over a 35P chrono twice, writing the velocity on the brass each time. Only kept the ones that had an ES of 0. Given the amount of brass involved (2k piece lots), the caliber (6.5-06 Imp) and the instrumental accuracy of scales and chronos available at the time (this was 12-15 years ago)... I had a very hard time believing that even consigning a barrel to its fate as a test platform would result in anything approaching repeatable velocity results over 4000 rds of 6.5-06 AI. The very few other people I ever encountered that tried replicating the process had minimal success.

Seems like you're having pretty good results with your approach, so I'm curious as to the particulars of how you do that portion of it (testing/sorting brass). Is it really just that - take prepped brass with a known-good load in a test barrel (old shot-out one, or new one that is a 'duplicate' of your match barrel, or your actual match tube?) and chrono'ing every single round, and keeping the most consistent for use in 'big' matches? Or is there something else to it - assuming that wouldn't involve spilling the magic beans

Monte

Monte,

My match rounds will normally have an ES of 6 or less. Usually much less. The brass once tested, will stay what it is as long as you properly maintain your cases ....Trimming, cleaning primer pockets, annealing, cleaning necks ect.


Once cases have been fireformed. I’ll sort and segregate them by weight into 5 groups of twenty pieces of brass. Lightest to heaviest. I’ll prepare the cases just as if I were taking them to a match and load them to the best of my ability. To test velocity I’ll use a barrel that’s lost it’s competitive edge. I’ll fire two shots down the barrel to bring it up to speed (with old set of brass). Then test the velocity 20 cases.

Shoot, then catch the piece of brass coming out of the gun. Then write it’s velocity on the side of the case placing it in the order it was shot into a loading tray. Once the string of 20 is shot I’ll clean the rifle and while letting it cool down, enter the speeds of each case into spread sheet. Then repeat!

Some Tips!

It’s best to run the test on a day where the temperature stays relatively the same.

The spreadsheet can help you sort out cases that want to play together and look for any other trends or anomalies.

I tried to short cut the process by recording velocities while fireforming! When I retested the fully fireformed brass the numbers didn’t correlate. So that was a waste of time.

Do not confuse low SD and ES with Tune!
Just because your bullets exit the barrel at the same speed doesn’t mean your gun is tuned. However, it is a validation of your reloading technique and the health of your rifle.

There I think I pretty much spilled the beans!

Bart

@Ned Ludd No offense taken! If you can see something else that you think can help or improve on this let me know.

 

[Dusty Stevens]

Bart takes my method to the next level. Ive always weight sorted then if i get a strange flyer i mark that brass with a sharpie and next time its loaded ill test it on the sighter- if it pitches again i pitch it

 

[mikecr]

I believe that if you proceed with cases matching in thickness, reset their energies with a deep body dip annealing, fire form them to stable dimensions and chamber clearances, and then pick out what matches in H20 capacities, there is a favorable likelihood of lowering case-born ES.

I agree that it's only confirmed with measure over a chronograph & target, and that this is not a shortcut.
It is just as gut wrenching to toss cases from a shooting bench, as from a reloading bench. So I salute those with the attention & discipline to do so.

 

[riflewoman]

There I think I pretty much spilled the beans!

Bart

 

[AckleymanII]

God help us!

I hope you evaluate the run out in front of the web of the case.

Sort cases by this run out.

 

[dnellans]

Monte,

My match rounds will normally have an ES of 6 or less. Usually much less. The brass once tested, will stay what it is as long as you properly maintain your cases ....Trimming, cleaning primer pockets, annealing, cleaning necks ect.

Once cases have been fireformed. I’ll sort and segregate them by weight into 5 groups of twenty pieces of brass. Lightest to heaviest. I’ll prepare the cases just as if I were taking them to a match and load them to the best of my ability. To test velocity I’ll use a barrel that’s lost it’s competitive edge. I’ll fire two shots down the barrel to bring it up to speed (with old set of brass). Then test the velocity 20 cases.

Shoot, then catch the piece of brass coming out of the gun. Then write it’s velocity on the side of the case placing it in the order it was shot into a loading tray. Once the string of 20 is shot I’ll clean the rifle and while letting it cool down, enter the speeds of each case into spread sheet. Then repeat!

Bart

Bart - reading between the lines here, does that mean you believe "everything else" about your case prep, loading, bullet selection, seating process is -less- of a variable when all stacked up, than the case velocity? While I think weight sorting is a good place to start, I'm not convinced the rest of my process is actually good (tolerances stacked) to actually see any changes specifically due to case volume. Unfortunately I don't have the luxury of shooting every round with a chrono and most of my cases end up all mixed up so the best I can do is sort into groups of 100 and try and mostly keep them that way.

 

[BartsBullets]

Bart - reading between the lines here, does that mean you believe "everything else" about your case prep, loading, bullet selection, seating process is -less- of a variable when all stacked up, than the case velocity? While I think weight sorting is a good place to start, I'm not convinced the rest of my process is actually good (tolerances stacked) to actually see any changes specifically due to case volume. Unfortunately I don't have the luxury of shooting every round with a chrono and most of my cases end up all mixed up so the best I can do is sort into groups of 100 and try and mostly keep them that way.

Oh, For! sure! I try to load every case as close as possible. Those variations are way less than what I see in a case variation. It’s not unusual to see 20 plus FPS difference in a set of 20 (after weight sorting).

You know it just depends on what you’re shooting. For Benchrest 600/1000 yards you can’t afford to have much more then a 15 FPS ES before your groups start to suffer.

Bart

 

[billslatteryjr]

This is awesome, thanks for sharing! I did start to measure case heads thickness -- which I thinkI briefly mentioned in the article. I didn't show data for it because it seemed like a different rabbit hole and I only started measuring after the 3X firing. I'll be more consistent about it for the second experiment.

I have a hunch that there may be something to it, but I need to dig into it.

I didn't know there was a special tool, but I've found that the gage pins I have work quite well with my digital calipers!

Eric, not special. These tools were of my own invention. Sure somebody else must have thought of the same thing somewhere along the line.
But like you said a tight neck fitting pin gauge with calibers would probably work better and faster anyway.
Bill

 

[Bindi2]

Oh, For! sure! I try to load every case as close as possible. Those variations are way less than what I see in a case variation. It’s not unusual to see 20 plus FPS difference in a set of 20 (after weight sorting).

You know it just depends on what you’re shooting. For Benchrest 600/1000 yards you can’t afford to have much more then a 15 FPS ES before your groups start to suffer.

Bart

F open is just belly bench rest. Bart is on the money. A chronograph is the next level up from scales. Can be done while practicing wind reading.

 

[billslatteryjr]

Oh, For! sure! I try to load every case as close as possible. Those variations are way less than what I see in a case variation. It’s not unusual to see 20 plus FPS difference in a set of 20 (after weight sorting).

You know it just depends on what you’re shooting. For Benchrest 600/1000 yards you can’t afford to have much more then a 15 FPS ES before your groups start to suffer.

Bart

Bart, how do you account for the effects of the primer on velocity? Do you find weight sorting primers takes that variable out of the equation? Or do you find using something like a K&M Deluxe is enough? Both? Neither? If neither do you mark a slow or fast case for repeated testing to help make sure it's not the primer that's causing the difference and not the case?

 

[Bindi2]

When you are on single digit ES the primers are working ok. I have never weighed a primer nor am I going too.

 

[dmoran]

When you are on single digit ES the primers are working ok. I have never weighed a primer nor am I going too.

That's all hunky dory when your on good primers (most are). Best also hope you never get a mediocre or bad Lot (occasionally show up).
While they may very well not hurt your score by much, you likely won't shoot your best on a mediocre Lot of primers either.
And a bad Lot, can leave you "soul searching", and in wrong directions - IME

 

[BartsBullets]

Bart, how do you account for the effects of the primer on velocity? Do you find weight sorting primers takes that variable out of the equation? Or do you find using something like a K&M Deluxe is enough? Both? Neither? If neither do you mark a slow or fast case for repeated testing to help make sure it's not the primer that's causing the difference and not the case?

Weight sorting primers is something that I should probably do, but I don’t. I’m using a 21st Century priming tool. I Seating primers until I feel the primer firmly bottom out on case. The Odd ball cases/results are retested. I can’t remember a retest that the results didn’t remain the same.

 

[Depart123]

Could not agree more. If you don’t have a nice way to provide constructive feedback that grows the knowledge within this community, then close your trap!

He is on Longrangehunter and the Hide as well, he does the same stuff everywhere he goes. I'm about to put him on "ignore" in all three forums.

 

[dmoran]

Weight sorting primers is something that I should probably do, but I don’t. I’m using a 21st Century priming tool. I Seating primers until I feel the primer firmly bottom out on case. The Odd ball cases/results are retested. I can’t remember a retest that the results didn’t remain the same.

Because I ran into a bad Lot years back (7% variation in weight) that had me scratching my head for part of a season, and because it only takes me around 3 hours to qualify 1000, I just do it to all Lot's. But in actuality, with Lot's that have say 3% or less variation from a 100-pack, likely don't need it. Worth checking at least 100-pack of every Lot (minimal advise), and I sleep better before a match knowing I have qualified them all.... lol