Hello gents
How different are different brands of brass when it comes to performance and accuracy?
I'm reloading for a couple of 270's, seems like everyone is right now . I have FC, WW and RP brass. The load I settled on is using the WW brass because that is what I had sized and primed. 1/2" groups at 3,070 fps with a 130gr bullet. Perfectly adequate.

I've often wondered how much brass plays a role, if any.
Thoughts?

Perry

Differences among commercial brass from those three makers will mostly relate to internal capacity and, possibly, brass longevity.

Significant differences in primer seating resistance or neck tension on bullets could translate in terms of accuracy. Not likely, IME, in a hunting rifle.

Average weight of your different lots will tell you something. Measuring internal capacity (water or some consistent drop powder) is better, will tell you more.

With certain cartridges like .308 (LC mil vs Win commercial) or .300 Roy (RP vs WBY) you can get in trouble by not factoring internal capacity.

FWIW, WW brass typically yields higher internal capacity than FC, Hornady, or RP.

Don't guess, tho.

Uniformity is the key; your brass sounds to be good in that respect; but if it wasn't of uniform weight (translating to internal capacity like he said above), then your results won't be as good. Maybe.
I assume you did not weigh them. For must uses it doesn't matter. Yes, military brass is thicker.
Uniformity.

Brass is heavy, much heavier than powder, so several grains weight difference in a centerfire case like a .270 makes little actual difference in case capacity. However, the shape of the case (and case head shapes do vary) can result in more variation in case capacity than simple weight differences. I know that doesn't tell you anything about what differences to expect between the three brands you name, but I thought it important to point out that case weight is not necessarily a constant indicator of case capacity.

I've found little difference in Winchester, Remington, and Federal brass insofar as accuracy potential. In general (and this certainly varies) Remington tends to be a bit thicker in the head, which would lead you to believe that it will withstand more pressure. However, Winchester tends to be harder in the head area, making it similarly strong. Some people dis Federal, but that I've used has proven as dependable as WW and RP.

There is no way to predict which will result in the most accurate loads in a given rifle, but the more consistent the brass in terms of weight, hardness, and shape (and preparation) the the better chance you have at good accuracy.

The big difference I've noticed over the past couple of decades is in metallurgy; I won't use RP brass that appears to be more than 30 years old, because of numerous brass failures in the old calibers I shoot--and using really antique stuff,from the old two-piece box era (around WW1), I've found the RP stuff goes fsssst! while the WW goes bang!, suggesting their primers don't last as long either. On the more modern stuff, I don't get as many loads out of CIL brass or PPU as I get from either RP or WW. No science, here, just consistent results over a lot of reloading.
windy

Yes no and maybe.

I have rifles that shoot well no matter what case you stuff the powder and bullet in.

I have rifles that are picky about it.

And all depends what you are trying to do Minute of deer out to a couple hundred yards.

Easy Minute of P dog out to hundreds of yards a lot harder.

The difference in maximum powder capacity will create a different amount of pressure if loading to the upper level of case capacity.
In general I have found Winchester brand brass to have a little higher capacity than the Remington, and close to the same in most cases, when using Federal brand also.
But this can vary by cartridge.
I have found Federal brand in the .300 win mag to have the primer pocket wear out sooner than some other brands.
I have gotten the longest use from Winchester in general, especially in the magnums.

I don't think anyone has scientifically proven brand x brass is the best in terms of accuracy.

As has already been pointed out, differences between brass brands do exist. For example, my pet load in 338 WM using Winchester cases is a maximum load of 67.5 grains of IMR 4350. I switched to Norma cases and using the same lot of primers, powder and bullets had to increase the charge weight by one grain to achieve the same velocity. I have weighed Winchester, Lapua, Norma and Nosler brass and Norma and Nosler were the most consistent in weight in 338 WM and 30-06. I didn't do an accuracy comparison between the brands, I just selected the brands which were most consistent in weight. Whether this makes a significant difference in accuracy or not I don't know but I like the idea of using more consistent brass.

Give yu an idea. Years ago I was collecting 06 and .308 brass for my X 41 wildcats.
After making up a bunch with no regard to manufacture I tried them in my 4 different calibers.
Not one of the four was MOA and these were unturned for finish ,heavy , Douglas supreme , floating 16" bull barrels..
After a little segregation and carefull loading !! Bingo!! First try on the 7X41 was MOA and later the 7.62, .358 and the .375X41 improved greatly with the segregation.
Later in life I found this to be true
on a number of other rifles.
On my 22PPC There is a vast difference between Norma cases and reformed 7.62x39 brass.The difference continued greatly between different manufactures of 7.62 X39 brass. We're talking wide spread performance in the 22PPC.If the cases are the same we mostly get MOA no matter the make..
22-PPC case volume
F.C. 7.62X 39 IMC 7.62X 39 nny 7.62x39 NORMA
Case weight 122.8 gr 125.8gr. 111.4 gr 28grains. IMR4895 completely fills FC. 7.62 x 39 cases
Case + water 154gr 156.5gr 145 grains. The nny and Fiocci cases have a head dia. .004" larger than the FC., IMC., Norma, and Winchester.
Water 31 gr 30.7gr 34grains Max loads are different between Norma and resized 7.62x39 cases. Volume difference and large primer vs small primers are the cause
Volumn 2.01 cc 1.99CC 2.14cc
Powders slower than 4350 do not perform well at all

Hope this helps. roger

RP brass is thicker than WW for instance so your supposed to drop the load by 2 grs. I don't doubt this but I don't abide by it either but I don't mix brass in any way..

I use, for instance, PPU in my 30-06 and my reloads all have the same number of firings, I don't however weigh cases..I see no reason not to keep track of firings as when the brass starts wearing out, I toss the lott or anneal it...For hunting big game I doubt if any of this balistice masturbation means anything at all...