Norma's additional cost is largely due to the projectiles. My experience with Norma v S&B brass is largely based on 22 savage and, to a lesser extent, on 308 win.
In both cases variability of the cases was identical ie weight of the unprimed brass, volumetric capacity in grains of water and overall length.
I had the opportunity to buy some norma brass for the 22 savage which is as rare as rocking horse crap and the cost was just £25 less per hundred for unprimed brass than for a 100 loaded S&B cartridges and the rrp of those was £240.
I bought the S&B cartridges and found the following, loading 10 cases repeatedly, I had 10 WW 22 savage Super X from the 1940s,11 Norma 5.6x52R from the last century and 10 S&B from this year.
To equalise matters I annealed all the brass and the WW and S&B have now been loaded 7 times, the Norma cases have been loaded 8 times. They all seem to have stretched equally.
I weighed a few samples of each,WW were the heaviest by about 1.5 grains, S&B and Norma were all within 0.5 grains of each other, Same with water capacity in grains with a 70 Hornady 0.227 bullet seated at the published COAL WW about 33.2 grains of water up to the primer hole, S&B and Norma 34.7 Grains water ditto.
The only thing that surprised me was the winchester brass lasted as long as it has, in my 30/30 and 308 it lags behind Federal and S&B my two principal case brands where federal is up to nearly 20 reloads, admittedly reduced power with cast boolits S&B not far behind if only because I started a good few years earlier with federal. Anyways, I've had 3 or 4 case neck splits with the winchester but none so far with the other two.
So my bet is the brass isn't worth fighting over, it being six of one and half a dozen of the other. Bullet wise, Norma isn't your budget friendly brand whereas S&B is and the reason is that probably S&B outproduces Norma by many times as it's a principal source of military ammo like PPU and,to a lesser extent, Lapua.
In the images below the left hand 3 are 22 savage cases, central 2 are S&B 5.6x52R cases and the remainder are norma, 5.6x52R. The die is a redding 22 savage trim die which I use to trim, funnily enough.
FWIW, and it's my opinion only, the only difference I can see between 22 savage and 5.6x52R is the very slight relief in front of the rim to enable the cartridges to function in break barrel guns with ejectors. Long ago I had a double rifle in 300 H&H rimmed and I can't remember that relief on those cases, but it was nearly 60 years ago and I only ever had factory loads so didn't perhaps pay as much attention as I do for reloading.
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