Just how much does "grouping" brass by manufacturer effect accuracy?

[AZAK]

Is there a noticeable difference in accuracy in rifle and handgun loads, when brass is consistent; as in from the same manufacturer?

When sorting/cleaning/inspecting brass, do you separate out the different brands?

For instance, I have noticed that in Federal .45 auto cases, that I have, that the flash hole is larger in diameter than in other brands of brass, again that I have. Will this make a noticeable difference in loading/accuracy?

Thanks! As I am still relatively new to reloading, still have to glean some wisdom from you experienced mentors; for a long time to come! And just trying to get into good habits from the start.

[darkgael]

There are shooters who, in the quest for better and better accuracy, will sort by manufacturer, weight of the case, etc.
Benchrest competitors are famous for this - but they are trying to put all their bullets through the same hole at 200 yards.
For me, life is too short to go to that much trouble. I have shot mixed brass from my .45s and new brass from the same lot and not seen any difference in accuracy. In target rifles, by default I shoot one manufacturer/one lot because I buy it by the case for my HBar.
In hunting rifles, I shoot mixed brass - one is as good as another. A note, though: I am not nearly as demanding about my groups as some shooters. Once I get to an inch, I'm good to go and off the bench into field expedient positions.
Pete

[wncchester]

I think it will decrease groups by .0136".

[ryalred]

I'm like darkgael. I try to stick with about three brands of brass (Winchester, Remington, and Federal) but I don't sort them. I know the bench rest guys do, but as I see it, if you go that route, you'll have to basically stick with one brand and discard the rest. Or you'll have to record how each brand of brass shot and then correct for the difference when you shoot.

[Jim Watson]

For a target rifle, dern tootin'.
Best to buy brass not only of the same brand but the same lot number.

For a pistol, not hardly.
A good bullet well seated is more important than the brass. NRA and PMA did a lot of work on .38 wadcutters and came to that conclusion. I find it applies to .45 ACP. At my level of expertise, anyhow.

[velocette]

With Rifle brass, different manufacturers cases will vary significantly in weight which means that they vary in case volume. It is considered customary to reduce max charges in military brass (which is usually the heaviest, thus has the least internal volume) by at least 1 full grain, more or less depending upon caliber. My experience has shown that by weight in 308, the military brass and Federal, the heaviest, are very nearly equal, then RP then Winchester then Hornady, the lightest. YMMV but thats what I've found.
Different case volume with the same powder charge will result in variations in the pressure curves, which will result in variations in velocity and / or accuracy.
With pistol ammo, I have not found significant differences between brands of brass.

Roger

[WESHOOT2]

Demonstrated: 9x19, 40 S&W, sorted cases matter, especially the 9mm.

To me.....

[Scope Bite]

For a revolver, I will sort by head stamp. -every time.

For an auto pistol, I will sort by head stamp.
-only when working up a new load. (not hot loads)
-I never sort semi auto brass once the load has been thoroughly tested. I just remove bad cases (or brands) from the mixed brass.

For all rifles, I sort by head stamp. For bolt/lever/pump rifles, I sort by times loaded.
-In an accurate rifle, you will see a difference between brands of brass with the same load. It might be point of impact, velocity, overall accuracy, or a mechanical issue. (feeding, extracting, loose primer pockets, etc...)
-In an inaccurate rifle, you probably won't see a difference, as long as the load is safe in all the cases being loaded. Such is the case when I load for autoloading rifles. I typically lose 25-50% of my brass when shooting in the desert with an auto rifle. As such, sorting cases by anything more than head stamp is a waste of time. (I don't run hot loads through autos.)

[AZAK]

I see that you are still online here. What about other pistol calibers? 10mm and .45auto are two that I am interested in.

And does the difference in the flash hole size make any difference?

Thanks!

[DEDON45]

For most pistol or plinking ammo (rifle), I don't really care to sort the brass...

Now, if I'm dealing with a Max load, or going for more precise accuracy, using the same lot of brass (same headstamp, similar internal case capacity, normally all bought at the same time) will definitely improve accuracy... when I do this, I get 6 fps extreme spreads (and a lot of dupe velocities) in 4 or 5 shots out of my .300 Weatherby (with trickled in pet charge), and the groups on paper reflect that.... with mixed brass, I get around 40 fps variation in my .44 Magnum (but that's close enough with a pistol, and for general use). Using the same headstamp brass, I get much tighter tolerances, and tighter groups, but in the .44, for what I use it for, I determined it wasn't worth the effort.

Currently I only keep my .300 Wby Brass sorted (which is easy right now, it's all Remington from the same lot), and a lot of .308 brass that I use for "match" loads. When I get my "fun gun" (a M1A is what I have my eye on) I'll probably have a batch of brass that's all mixed up, but that'll be for plinkin'.

[Loader9]

Rifle brass is the same brand and same lot. If I have different lots, it will usually be a different load with a different bullet. When I buy brass, I buy a lot and put it back for a rainy day. Pistol brass. Loading for a 45 ACP match pistol I've tested using different brass from Remington, Winchester, S&B, and military. It all goes to the same place on the paper at 25 yds. Despite there being no difference in my country testing, I still separate brass headstamps. Old habits are hard to break.

[444]

Yes, it makes a difference.

Depending on what you are doing with it, it may or may not be worth the effort. For the VAST majority of people , rifle accuracy is judged by 100 yard groups, which is far from the most demanding application.

I have a very good friend that shoots NRA F-Class (1000 yards). Ensuring that the cases are all manufactured by the same company and weighing them is just the beginning of what he does. After that he measures case run out as well as the run out of the loaded round (how straight is the case).
When you are shooting at 1000 yards, these things make BIG differences. If a piece of brass doesn't make the grade, he throws it away. He is not handloading for economy. He is handloading ammo as good as he can possibly make it and the result shows on paper and in his scores. There are many variables in precision rifle shooting. Any one that you can eliminate or reduce is worth it.

Even if you needs are much more mundane, I personally make every effort I can to load the most accurate ammo possible. I don't have a problem taking a few extra steps to go beyond the minimum nessessary.

[D. Manley]

Significant factor in rifle accuracy, less so in handguns. I frankly cannot tell the difference in handguns...if it's there, my guns or my shooting abilities (or, both) aren't good enough to make any difference show up. Even so, I still sort handgun brass by headstamp...gives a 2nd chance to inspect cases and sort out any problems before they end up in a chamber.

[WESHOOT2]

But maybe not 'size'; perhaps more 'clean edges'. Some find flash hole uniforming enhances accuracy.

I can not discern any accuracy difference with mixed cases in 45 ACP; I sort all 10mm.

(I don't --normally-- sort 38 / 357 Magnum / 44 Magnum / 45 ACP).