Weighing brass

[Clem Bronkoski]

What is the purpose of weighing brass? Is it done to validate uniform case capacity - ergo less pressure variance?
I just recently got into this long range shooting and still learning a lot even at 72! I am using Starline brass in my rifles except for my 300 WM which I'm using Petersen brass. I do have some Hornady.
So if weighing brass is that important, what plus/minus tolerance do you consider allowable? And if you do sort by weight what do you do with the ones that are above or below your nominal weight?
A lot of questions I know but I want to eliminate as many variables as possible.

 

[Shane Lindsey]

I do not do it on quality brass.
I recently weighed some Rem brass. The difference was not much at about 6gr spread. This isn't for a long range rifle though.
Did it to ensure pressures/velocities would be close due to case capacity. Too lazy to put water in all of them.

As for ones that are way light or way heavy, they are still good. Just use them for fouling rounds.

 

[BRADMOTO]

Waste of time. I had heavier cases show the same water capacity. It's the capacity that matters most. So, just because one case is heavier than other doesn't automatically mean it's reduced volume.

 

[Clem Bronkoski]

Brad I'm thinking along the same lines. Especially when talking about quality brass. I'm sure there are capacity differences in brands due to brass thickness and new vs fire formed.

 

[Turpentine21]

For quality brass you won't see much variation. But if you are running Hornady from different lots and Winchester even from the same lot there is enough weight difference there to indicate an anomaly in the case. I buy a good bit of once fired brass that I will use for practice. I also use Lapua Brass for more serious long range hunting. I don't weigh Lapua. In the once fired from different lots you will get better ES and Sd if you weight sort and will also get less flyers. I have also weighed new Winchester brass from the same lot that would have a couple cases out of 100 that would weigh 10 grains off of the average. I've opened those cases up and found differences in case web thickness along with other issues. With high quality cases. Weighing makes very little difference. For "once fired" range brass and in some new brass it certainly will make a difference.

 

[BRADMOTO]

For quality brass you won't see much variation. But if you are running Hornady from different lots and Winchester even from the same lot there is enough weight difference there to indicate an anomaly in the case. I buy a good bit of once fired brass that I will use for practice. I also use Lapua Brass for more serious long range hunting. I don't weigh Lapua. In the once fired from different lots you will get better ES and Sd if you weight sort and will also get less flyers. I have also weighed new Winchester brass from the same lot that would have a couple cases out of 100 that would weigh 10 grains off of the average. I've opened those cases up and found differences in case web thickness along with other issues. With high quality cases. Weighing makes very little difference. For "once fired" range brass and in some new brass it certainly will make a difference.

I've bought several thousand once fired Hornady. The cases they use for TAP are heavier by 20gr. The regular variety weigh 170gr ave. The TAP 190gr. Now, there is a 10gr variance amongst both weights. They both have same H20 capacity. I need to cut some in half, but I suspect the weight difference is in the web/case head.

 

[Tiny Tim]

Weight of water capacity is what is most telling as others have pointed out. They must all be of uniform dimensions as well to accurately measure this. This means new unfired brass from the same lot/manufacturing machine, or best case, fired in your chamber. Purchased once fired brass has no guarantee of being fired from the same chamber, and thus may be dimensionally different. Once getting to the point where these measurements are distinguishable to your shooting system, all variables must be minimized as much as possible.

 

[Hugger-4641]

As mentioned, quality new brass weighing not needed. I do weigh my cleaned once fired or range brass. I separate into groups of +-3gr. So if I have 100 rds with a 10gr spread, which is common, I've usually seperated into two groups, but I may fudge the overlap a little if needed to get 50rds in each group.
Case capacity is the main reason, but I also wonder if a big weight difference also affects case expansion during firing.

 

[LongRangeRookie]

I do weigh different lots of brass (same manufacturer of course) after forming and trimming to a uniform length.
When checking different manufacturers cases I see some with a big variation and others much smaller. My goal here is to eliminate anomalies and increase consistency.
For me reloading (for accuracy) is all about consistency, and weighing brass of the same lot gets a more consistent range of volume without measuring volume specifically, kind of a time vs results in larger volumes.
I have found (for example) that the good brass for my 308 Win is Lake City which I then sort by lot (say LC 15) and then I sort by weight - usually the weight is in groups of less than a grain - depending on the number of cases I have of each weight range. This is much faster than trying to check volume individually and the accuracy of the loaded round has shown to be very good.
I load accuracy batches of 308 and volume batches of 308 - the time for loading each varies greatly because I focus more time on sorting and measuring all of the components for the accuracy batches to hopefully eliminate anomalies.
I load for more than one 308, but I only focus on accuracy for one gun. This changes my outlook for loading for the 308.
My process for batches of other cartridges (say 300WM or 338 Lapua) is different because I only load for accuracy in those cartridges and only for one gun in each cartridge.
I have tested and invested much more in these individual components so I expect more from these reloads. The intent of these batches is focused almost entirely on accuracy - also the cost to shoot those cartridges is not cheap.
Cost isn't the primary goal, but what I want to accomplish (accuracy) is different. I usually shoot for extended distances - accuracy at a 1000yds is more of what I expect for them. Interestingly, I have checked the case weights in the Lapua and Peterson brass I use in the 300WM and 338 Lapua and the variation is much smaller in these brands than what I have seen in many other manufacturers.
Just my 2 cents on weighing cases - it works for me..

 

[Lionel Boyd Johnson]

As has been said, the water capacity of the case is the important variable especially for longer range (beyond 600 yards from my shooting experience). For shorter ranges, I've found that the heaviest cases shoot into the same group as the lightest ones. You could try this experiment with your lot of brass to put your mind at rest.

 

[Gpkhill2]

It's all about water capacity. The weight of the case itself really doesn't matter as long as they all have the same internal capacity. The thickness of the rim can change the overall weight but still have the same internal capacity. Obviously I think that if you use premium brass ie Lupua,ADG,Peterson,Alpha there is no need to check them.

 

[Gpkhill2]

I do weigh different lots of brass (same manufacturer of course) after forming and trimming to a uniform length.
When checking different manufacturers cases I see some with a big variation and others much smaller. My goal here is to eliminate anomalies and increase consistency.
For me reloading (for accuracy) is all about consistency, and weighing brass of the same lot gets a more consistent range of volume without measuring volume specifically, kind of a time vs results in larger volumes.
I have found (for example) that the good brass for my 308 Win is Lake City which I then sort by lot (say LC 15) and then I sort by weight - usually the weight is in groups of less than a grain - depending on the number of cases I have of each weight range. This is much faster than trying to check volume individually and the accuracy of the loaded round has shown to be very good.
I load accuracy batches of 308 and volume batches of 308 - the time for loading each varies greatly because I focus more time on sorting and measuring all of the components for the accuracy batches to hopefully eliminate anomalies.
I load for more than one 308, but I only focus on accuracy for one gun. This changes my outlook for loading for the 308.
My process for batches of other cartridges (say 300WM or 338 Lapua) is different because I only load for accuracy in those cartridges and only for one gun in each cartridge.
I have tested and invested much more in these individual components so I expect more from these reloads. The intent of these batches is focused almost entirely on accuracy - also the cost to shoot those cartridges is not cheap.
Cost isn't the primary goal, but what I want to accomplish (accuracy) is different. I usually shoot for extended distances - accuracy at a 1000yds is more of what I expect for them. Interestingly, I have checked the case weights in the Lapua and Peterson brass I use in the 300WM and 338 Lapua and the variation is much smaller in these brands than what I have seen in many other manufacturers.
Just my 2 cents on weighing cases - it works for me..

You weight your cleaning patches don't you

 

[Clem Bronkoski]

Well right now I have 200 pieces of Petersen brass for my 300 WM which is the one I'm really focused on. I'm still doing load development for it and once I find my load and have all my new brass fire formed and trimmed I should be ready to go. I also have a big batch of Hornady once fired brass that I will fire, trim then weight sort and use only for practice. My Petersen will be for hunting only and prehunting practice to insure I have the right DOPE.
My goal is accuracy and precision with this rifle. You have to have both.

 

[LongRangeRookie]

You weight your cleaning patches don't you

I sort them by size first, then weigh before and after I use them to see how much I am pulling out of the barrel - you don't?