Hi,

I have a question; is a difference of 4,6 Grains in the case weight to much for 300 WM cases. I have a weight between 261,4 grains up to 266 Grains.
Does this have any influence on the accuracy on the shooting? And if - how much at 100 yards?

BR John

Hope this doesn't come off as too flippant, but sort them by weight and see for yourself

With that big ole case, at 100 yds, I'll bet you can't tell much difference.

-nosualc

quote:

I have a weight between 261,4 grains up to 266 Grains.
Does this have any influence on the accuracy on the shooting?

Sorry the anser I have is: "It depends" I've had rifles that cared other that didn't. I'd be more worried at 300yds than 100.

I don't weigh cases. But then, I don't uniform primer pockets nor other idle waste of time.

As posted, load up 10 of the lightest and 10 of the heaviest and see how they do. Oh yes, load up 10 mixed. It'll make for a interesting experiment and get you to shooting more.

That much difference in weight of the brass translates to something less than 2g of internal water volume. I use a variance of ±3g as a benchmark. In that area I've never noted any difference in velocity or performance. When it gets above that in cases of that size, and larger, it's dicey. Sometimes a difference of 4 or 5g of water volume will require a minor tweak of a half grain of powder to either maintain velocity or restore extreme accuracy. Use them the way they are. I'll bet you won't see ANY difference.

The weight of the case may or MAY not have anything to do with internal volume. It is a feel good task so to speak..

True. The only place that WILL make that difference however, is in the extraction groove or the head, both of which can vary, some significantly. By and large, from the same case lot and from manufacturers of reasonable quality, it's usually VERY close. This is why checking internal water volume is preferable.

You bet!! The sun is shining, no breeze, 78 degrees and I'm gonna be sitting at a reloading bench with an eye dropper and a pan of water. It just ain't gonna happen!

I'm gonna load me some ammo and go to the range. If I get an unexplainable flyer, I'm gonna mark that case and give it another chance when I reload. If it is still a flyer on the next go, it gets pitched into the scrap bucket. Unweighed, as it were.

Thanks for your answers - they are loaded and will be fired

quote:

Originally posted by jola:
Thanks for your answers - they are loaded and will be fired

If you weighed the cases individually, I hope you weighed the bullets individually, too. Bullet weight is likely to have a much greater effect on your results.

Good Luck,

Happy New Year

Lost Sheep

quote:

Originally posted by wasbeeman:
I'm gonna be sitting at a reloading bench with an eye dropper and a pan of water. It just ain't gonna happen!...If I get an unexplainable flyer, I'm gonna mark that case and give it another chance when I reload. If it is still a flyer on the next go, it gets pitched into the scrap bucket. Unweighed, as it were.

Same here - except - I do Weight Sort my cases(without putting water in them). And I'm real happy with the results.

The long and the short of it

In prehistoric times, when I was learning to handload rifle cartridges, it used to be worthwhile to weigh cases. The reason was that cases that varied considerably in weight also varied considerably in volumetric capacity--or internal dimensions, although this is not guaranteed. Some weight gain can be in the head and not affect capacity --still we did look for considerable differences in weight. These days there is not a lot of reason to weigh cases unless you are picking up brass at the range or use the really cheap stuff that is still drawn on the old sloppy dies. We were always aware that a .5 grain weight of brass variable in no way translated into a .5 cubic inch variable in capacity. Hint: it's a lot easier to do these calculations in metric where .5 gram weight of the constant (water) is also .5 of volume as expressed in cubic centimeters.(cc) You can actually calculate the change in volume by change in weight to a certain degree in metric--if you have calculated your powder density in % of the constant, which you should be doing anyway, for other reasons. I 've done it--it's insignificant inside a 5% variation.

Therefore many folks, including the one who taught me about handloading, adopted a 5% rule. This stipulated that all weights and measures were acceptable within 5% of the mean. This would translate as follows: If I had 100 6mm PPC cases that weighed from 98 grains to 103 grains, with the highest number of cases weighing 100 grains, we would accept 100 grains as the mean weight of 100 cases, 100.5 grains being the average. So-- 100 minus 5% is 95 grains and plus 5% is 105 grains. All the cases were usable. ----and so they were, too-----You can actually calculate the change in volume by change in weight to a certain degree in metric-it is easy-I've done it--it's insignificant inside a 5% variation.

In a recent seminar given by a world class BR shooter, Jack Neary, it was mentioned that he does not bother to weigh brass anymore. Please note that he is not using cheap brass. Also note that he is alert to any variation in group size down to the tenth of an inch at 100 and 200 yards, using a case where a capacity change of .3 grains is a lot more significant than a the same in 300 WSM.

So--doing the calculation the short fast fairly accurate way--using SAE--we can see that a 4.6 grain weight variance in a 300 WSM case does not translate into a 4.5 cubic inch difference in volume or a 4.6 gr. difference in powder capacity. Assuming the average is also the mean weight (263.7 gr.) for your cases we would look for a +\- in excess of 13.185 grains before deciding to cull a case.

Case weight has long been a whipping boy for poor accuracy. Folks would be better served if they looked at other factors--mainly pilot error, but that's another subject entirely.

"pilot error" I like that.

There comes a time when the shooter has to be realistic about a few things. How good is the gun and cartridge? How good is the shooter? What is his real target and goal?

If his target is paper and his goal is 5 shot, one-hole groups, he needs to buy his gun somewhere other than Wal-Mart or Sportsman’s. Otherwise weighing cases doesn’t really add up to much.

Good post amamnn!

quote:

Originally posted by MickinColo:
There comes a time when the shooter has to be realistic about a few things. How good is the gun and cartridge? How good is the shooter? What is his real target and goal?

If his target is paper and his goal is 5 shot, one-hole groups, he needs to buy his gun somewhere other than Wal-Mart or Sportsman’s. Otherwise weighing cases doesn’t really add up to much.

Good post amamnn!

Accurate handloads help me to shoot better than otherwise. By narrowing the grouping, the better is the hunt!

quote:

Originally posted by MickinColo:
There comes a time when the shooter has to be realistic about a few things. How good is the gun and cartridge? How good is the shooter? What is his real target and goal?

If his target is paper and his goal is 5 shot, one-hole groups, he needs to buy his gun somewhere other than Wal-Mart or Sportsman’s. Otherwise weighing cases doesn’t really add up to much.

Good post amamnn!

quote:

Originally posted by rcamuglia:

quote:

Originally posted by MickinColo:
There comes a time when the shooter has to be realistic about a few things. How good is the gun and cartridge? How good is the shooter? What is his real target and goal?

If his target is paper and his goal is 5 shot, one-hole groups, he needs to buy his gun somewhere other than Wal-Mart or Sportsman’s. Otherwise weighing cases doesn’t really add up to much.

Good post amamnn!

quote:

Originally posted by vapodog:

quote:

Originally posted by rcamuglia:

quote:

Originally posted by MickinColo:
There comes a time when the shooter has to be realistic about a few things. How good is the gun and cartridge? How good is the shooter? What is his real target and goal?

If his target is paper and his goal is 5 shot, one-hole groups, he needs to buy his gun somewhere other than Wal-Mart or Sportsman’s. Otherwise weighing cases doesn’t really add up to much.

Good post amamnn!

Oh yeah? Well....

Some things are easy to agree on!

quote:

There comes a time when the shooter has to be realistic about a few things. How good is the gun and cartridge? How good is the shooter? What is his real target and goal?

If his target is paper and his goal is 5 shot, one-hole groups, he needs to buy his gun somewhere other than Wal-Mart or Sportsman’s. Otherwise weighing cases doesn’t really add up to much

Is it scary when this many of us agree on something???