How precise on weighing cases?

[OKyote73]

Waiting on a stock for my "new" to me 20/222. Just weighed 100 win cases, 92.1 to 94.7grs. Most fell into two areas tween 93-93.6grs and 93.9-94.6grs. What to do?? TIA

[Bill K]

Make a ladder load on the weights and see if it does or does not make enough difference to fool with, for your purposes. Bill K

[jepp22]

This is the best advice I have run across and what I follow. Unclenick on TFL provided it, so thanks go to him.

"Cartridge brass density is 8.53 gm/cc, according to Matweb. That means 0.853 grains, in identically trimmed and primer pocket uniformed cases, will represent 0.1 grains difference in powder space. Since pressure goes up exponentially with increase in powder charge, this is about like a 0.05 grain charge difference. Not usually a significant error. If you charge cases ±0.1 grains, then figure cases ±1.7 grains are roughly equivalent to that."

[Daryl]

I don't weigh the cases for my Sako L1 .222. With good loads it will still shoot 1/4" or very slighlty larger 5-shot groups at 100 yards. I don't clean primer pockets or brass either and dump all charges using a 1968's RCBS Uniflow measure- mind you, I am quite consistent with it - lots of practice.

For BR Competition, perhaps weighing everything is necessary - for shooting rats, I think it's a waste of time.

[Iowa Fox]

Just my thoughts. If your shooting 100 yard benchrest and use 20 hand make cases for the season- maybe. Anything else, other things will give you a greater return on investment (accuracy) of time and money.

[ramos]

Harold, I'm just gonna take your' word on that. You lost me immediately after: Now for the statistical treatment of the data -

And I even enjoy math!

Now, I am going to play Devil's Advocate. Since I am the Devil, I don't have to provide any supporting data! If you have an extra step during prep that you enjoy & it adds to your' confidence in the finished product, do it! The peace of mind and confidence gained is necessary to shoot tiny groups. Just how much difference will it make? Well, remember I am playing the role of the Devil here so, I don't have to quantify or prove anything......


Safety first and foremost, then it's all good!!!

[Kevin Gullette]

I feel I get more info from sorting by neckwall thickness runout.

Numbers on cases are tenths, T.I.R.

Kevin

[Bayou City Boy]

To add to what Harold said, even if you control all other sources of variations in the cartridge case that might affect accuracy, the effect of weighing and sorting individual cartridge cases is negligible at best.

For me there are far more important things than weighing cases to insure relatively short range (inside of 600 yards) hunting accuracy. If you’re consistently shooting 600-800 yards+, uniform case weighing might provide a relatively small amount of accuracy potential, but at normal varmint shooting ranges, the effect is very minimal if it exists at all.

If you rely on the cases all being the same weight, you are assuming that all of those same cases must have identical volumes. Using water or some other media to compare individual case volumes, you’ll find that cases with identical weights won’t necessarily have identical volumes. This is true for both large and small volume cartridge cases. For me, far more important than case weight is case volume. And no, I don’t sort case by volume either for my varmint shooting purposes either.

Case volume, coupled with diligent neck work that insures minimal runout from one cartridge to another and holding the same neck thickness and the same neck tension from one case to another are also far more important than case weight uniformity from one case to another. In addition, flash hole deburring and size uniformity will provide more reliable accuracy than case weighing will. A common tool for serious BR shooters isn’t a good scale to weigh cases. Instead it’s a bullet seating tension gauge to insure uniformity in neck tension from one case to another, assuming uniform bullets are being used; which in itself is another variable that can affect accuracy to a greater extent than case weighing will. Even the number of times that brass is fired when comparing one case to another will affect accuracy more than any variations in individual case weight will. So once again, even if you control all other sources of variation, the effect of brass weight is negligible for varmint shooting.

All that said, if weighing cases makes you feel better about the ammo you produce, you should probably continue to do it. If you’re doing it because you don’t have anything else to do during the cold winter months, I’d recommend another hobby to occupy you and to maximize the value of your time until spring rolls around.

For me personally, I’d rather be fishing or playing golf than being anal about weighing cases that likely have different case volumes and far greater unresolved case neck issues that affect normal varmint shooting accuracy far more than whether or not all the cases weigh the same. But to each their own………..

-BCB

[WayneShaw]

I have seen significant differences in benchrest shooting. To assume this beloved Lapua is "so close it's a waste of time" is a mistake. I've also seen different lots of brass show surprising difference on average.

Winter is coming. Weigh them, sort them. Take the question out of you mind.

[Bayou City Boy]

As Wayne stated, there's no doubt that there is a world of difference between BR and varmint shooting.

-BCB