Who here weight-sorts cases? Has it made a difference in accuracy? I have a new batch of Lapua 6.5x55 cases that are pretty uniform in weight. (This is after I've trimmed and neck-turned them.) The range in weight, from lightest to heaviest, is a little over 1.0 grain. If I weight-sort them into two groups, lighter and heavier, the range in weight in each group drops down to about .5 grains. So, if I shoot 5-shot groups, the maximum case weight difference within the group will be .5 gr., and for most groups, less than that. Is this much reduction in case-weight variation likely to lead to improved accuracy? What are your thoughts on weight-sorting brass.
Weight-Sorting Cases: Is it Worthwhile?
- Thread starter South Pender
- Start date
Me too. My understanding is volumetric sorting is a better indication of case capacity but the more knowledged will post here soon enough I am sure. In the absence of that, weight sorting I think offers some merit. I have started that lately but have no firm numbers or paper examples to show significant difference...for the rigs I shoot.
Regards
Ronr
back40sniper
CGN Regular
- Location
- South east Sask.
I am with Gatehouse on this one, Lapua is good to go out of the box. Unless you are competing "way out there", then internal capacity is what you will be measuring.
I have found sorting my 300 Savage and 243 Winchester brass by weight makes a noticeable difference in accuracy at 100 yards. The Gevelot 300 Savage brass weighs many grains more than my Remington or Dominion brass. I want to say significantly more but i would have to check my notes. This is with Varget and 150 gr projectiles.
Same for my 243. I now sort my rifle brass when reloading.
YMMV
Same for my 243. I now sort my rifle brass when reloading.
YMMV
It's the volumes that you want to be close, but weight is (in my experience) a good indicator of volume, but it's not a direct correlation.
Brass from the same manufacturer and same lot is generally very close - you could weigh a few random pieces and see, then check the volume of one of them by weighing it empty (with a spent primer in place) and then filling to the top with water and weighing it again. The difference in weight is the grains of water capacity to the top. I then will fill it to the place where the bottom of the bullet would be and weigh it again, and that would be the "usable capacity". Water has a density of 1.0, so if its capacity is 50.0 grs of water (for example), and I'm using a powder with a density of 0.9, then I know that that cartridge can hold 50 grs/0.9 = 55.6 grs of that powder before I'd be compressing it.
Whenever changing manufacturer and to a lesser extent lot, don't just use the loads you developed previously. Volume can vary quite a bit (5-10%), so do the above and compare with the brass used with the previous loads first.
Here's an example of what you might see: https://www.canadiangunnutz.com/forum/showthread.php/1120440-Some-7X57-Case-Capacities?
Brass from the same manufacturer and same lot is generally very close - you could weigh a few random pieces and see, then check the volume of one of them by weighing it empty (with a spent primer in place) and then filling to the top with water and weighing it again. The difference in weight is the grains of water capacity to the top. I then will fill it to the place where the bottom of the bullet would be and weigh it again, and that would be the "usable capacity". Water has a density of 1.0, so if its capacity is 50.0 grs of water (for example), and I'm using a powder with a density of 0.9, then I know that that cartridge can hold 50 grs/0.9 = 55.6 grs of that powder before I'd be compressing it.
Whenever changing manufacturer and to a lesser extent lot, don't just use the loads you developed previously. Volume can vary quite a bit (5-10%), so do the above and compare with the brass used with the previous loads first.
Here's an example of what you might see: https://www.canadiangunnutz.com/forum/showthread.php/1120440-Some-7X57-Case-Capacities?
Last edited:
I weight-sort all the time, however if you purchase Nosler, Peterson or Lapua brass, there will be very little need to weigh. I've experienced great consistencies with Nosler and Lapua, Peterson a very close third. Weight sorting is a means of preventing inaccuracies of load development, the same would apply to bedding and free-floating a barrel. These measures don't make your rifle more accurate, it prevents it from being inaccurate.
I weigh sort into 2 groups, with Alpha and Lapua, from these there will be 2-5 outliers in weight, these are used for dummy rounds etc.
From these, the batch of brass is velocity sorted (over a Lab Radar), again checking for outliers.
Along with other benchrest handload techniques I've found that fliers are very much reduced by taking these additional steps.
As a side note out of 150 bulk Remington 300 WM brass there was ~40 pieces that got used in competition.
From these, the batch of brass is velocity sorted (over a Lab Radar), again checking for outliers.
Along with other benchrest handload techniques I've found that fliers are very much reduced by taking these additional steps.
As a side note out of 150 bulk Remington 300 WM brass there was ~40 pieces that got used in competition.
- Location
- Western Manitoba
I suspect has a lot to do with what rig is eventually being fired in, and competency of that shooter. Many bench rest reloading techniques that I have tried, just show no difference on the targets that I have shot - so me and my rifles can not show how some particular fussing is of any consequence - other fussing is well worth it - I can show difference on target groups. I am not disputing that Speedy Gonzales can show a difference when he shoots his rifles - I am not there yet - maybe, I never will be - so, for me and most of my rifles, much of it is a waste of my time.
For perspective - I am very pleased to get 1" 5 shot groups at 100 yards - tend to be a bit disappointed with 2" groups - but have taken deer with even worse than that. I am not trying to improve my scoring average from the "twos" into the "teens" - so what is needed to do so, is different, no doubt.
Last edited:
Definitely for Lapua, Nosler and Norma brass, it does not make any difference. 99% of Lapua brass will be +/- 0.5 grain from average. With other brass the difference in weight can be significant (Win, Hornady, etc..).
I watched Eric Cortina once. He said he used Lapua brass. He did not weigh and did not do ANY prep with it. If a match shooter does that, a hunter can do it too.
I watched Eric Cortina once. He said he used Lapua brass. He did not weigh and did not do ANY prep with it. If a match shooter does that, a hunter can do it too.
https://i.imgur.com/n2BDaS4_d.jpg?maxwidth=520&shape=thumb&fidelity=high
The only difference in these three, five shot groups is bench technique.
So there is some accuracy to be found there.
The only difference in these three, five shot groups is bench technique.
So there is some accuracy to be found there.
Recently, I weighed 75 Nosler brass (box of 25) for the 300 H&H, the difference of all the brass cases was 0.8 of one grain. Now that is excellence for such a very long case! I also weighed 50 Peterson brass for the 270 Win., the difference was 1.1 grains, still very impressive!
A friend and I did a little experiment 25 years ago using weight sorted and unsorted brass.
At 200 meters, using a Krieger 308 barrel on a Sportco action , benched with an accurate IOR 9-36x scope .
He loaded and recorded the ammo and groups,and I shot, not knowing what ammo I was shooting .
There was no difference in accuracy in the weight sorted ammo and the unsorted brass of the same brand .
IMO sorting brass in a hunting rifle is time wasted that could be put to better use.
Cat
At 200 meters, using a Krieger 308 barrel on a Sportco action , benched with an accurate IOR 9-36x scope .
He loaded and recorded the ammo and groups,and I shot, not knowing what ammo I was shooting .
There was no difference in accuracy in the weight sorted ammo and the unsorted brass of the same brand .
IMO sorting brass in a hunting rifle is time wasted that could be put to better use.
Cat
Last edited:
I have about 1800 .308 Lapua cases from several different lots. They weigh between 170 gr to 174 gr. Sized and trimmed without a primer, I sort within .5 gr. Everything goes into MTM boxes and marked 170 L for anything between 170.0 to 170.4. Also have boxes marked 170 H for cases weighing between 170.5-170.9. Same for all other weight. Out of all of these cases the largest batch is 173 gr.
At 100 yards you probably won’t see much difference with a mix weight lot of brass. However in my mind it does make a difference at 1000 yards.
I also understand that sorting by volume would be a much more accurate way of sorting, but who has time to sort 1800 cases by volume?
At 100 yards you probably won’t see much difference with a mix weight lot of brass. However in my mind it does make a difference at 1000 yards.
I also understand that sorting by volume would be a much more accurate way of sorting, but who has time to sort 1800 cases by volume?
I totally agree Maynard, the difference can be seen out to 1K, but even then , depending on the skill of the shooter, I don't know just how much difference it would make.
However it does take out that variable .
I really think too many newer shooters have been watching to many of the wrong videos on accuracy these days and have forgotten to learn the rudiments of shooting first before jumping to procedures that will not make the difference in their shooting.
I see it every day at our range....
Cat
Last edited:
I do this for anything I want the best accuracy out of. - dan
Sorting by volume is a waste of time. Volume is ultimately controlled by the chamber in your rifle which the case under pressure will expand to fill.
Once that occurs, the only volumetric value that is relevant is the amount of brass that also occupies space within the chamber. This is reflected by its weight.
Not to mention that using water weight to measure volume cannot be reliably weighed to a closer accuracy than what you attempt to control by this effort. Bubbles or inconsistent meniscus will likely exceed the variance you look to identify. In this sense, sorting by water weight is actually sorting by the error in the method you are using to sort, and not any meaningful value.
Measuring cases by volume is a nice way of ball parking volume for the purpose of predicting pressures using software like QuickLoad, but volume measurements should be limited to this context.
In the end, there is such a negligible dimensional difference between external dimensions of cases that you can dismiss machining tolerances as the source of volumetric variance. This leaves weight (as a reflection of internal dimensions) as the only reliable factor as it applies to variation in volumetric displacement and there for its affect on velocity.
I sort my competition cases to within 1/10th of a grain by weight after full process reload. Once they have been fire formed twice, they mean something to me.
Last edited:
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Case volume is like the cylinder volume in an engine and ask any engine builder for race cars... it matters and balancing this is important.
However, the difference in case volume within a batch of well made brass is nearly insignificant even if the case weights might differ.
If you really want to compare cases, then with fireformed cases that were previously trimmed to length... leave the spent primer in the case, fill with a very fine powder (like salt). Tap the case to ensure everything has settled. Level with the top of the case mouth. Dump into the next case... it might overfill... tap for it to settle.. compare level.
On a 308win case, if the level varies more then 2mm, I will put that case aside. In the many cases I have tested, I have seen very few that actually varied... so don't bother when using quality brass AND seeing consistent impacts on target.
Might be a way to sort range pick up with the same headstamp?
it is just cheaper to buy good brass
Jerry
PS... weight sorting was the simple solution to a messy method of using water/alcohol to measure case volume. I just made my life easier by going to a super fine ball powder and doing a relative comparison. Fast, simple and tells me something useful
However, the difference in case volume within a batch of well made brass is nearly insignificant even if the case weights might differ.
If you really want to compare cases, then with fireformed cases that were previously trimmed to length... leave the spent primer in the case, fill with a very fine powder (like salt). Tap the case to ensure everything has settled. Level with the top of the case mouth. Dump into the next case... it might overfill... tap for it to settle.. compare level.
On a 308win case, if the level varies more then 2mm, I will put that case aside. In the many cases I have tested, I have seen very few that actually varied... so don't bother when using quality brass AND seeing consistent impacts on target.
Might be a way to sort range pick up with the same headstamp?
it is just cheaper to buy good brass
Jerry
PS... weight sorting was the simple solution to a messy method of using water/alcohol to measure case volume. I just made my life easier by going to a super fine ball powder and doing a relative comparison. Fast, simple and tells me something useful
