I had to take a heart pill yesterday. I was weighing some 7mm Rem Mag finished ammo, which I usually do for hunting rounds just to be sure. They seemed fine and uniform at 445-446 gr per round. Then memory kicked in and I recalled that this load usually weighed more, around 485-486 gr. I checked some, and sure enough. Momentary panic! It took only a couple of minutes to discover that the 40 gr difference was in the Nosler cases. The older lot weighted 261 gr, the newer one 221. There was my 40 gr difference.

I called Nosler. Yes, they answer the phone and are most helpful. The tech explained what we all know, that weight differences are dependent on the alloy used, which can vary. He was surprised at the amount of weight difference, around 15%, and asked for lot numbers, which I supplied. He assured me that each brass lot is pressure tested at their facility and is safe.

Another clue, which I brushed off, was load density. The previous batch was 93% and the latest was 88%. I chalked it up to measurement error, but it was true.

It will be interesting to see the chrono results on the new batch. This is hunting ammo, not likely to be used beyond 300 yards, so I doubt there will be a significant performance difference. At 1000 yards, that could be different.

I also learned from Nosler that Norma does not make their brass, but that the companies work together closely, sharing technology. Nosler makes its own brass and ammunition in a plant in Redding, OR, 20 miles from the main facility in Bend. They are expanding that plant substantially.

Perhaps too much info, but you didn't have to read it. No quiz on Friday.

Helpful and interesting, thank you. I am happy that I can get 280 Ackley brass.

Wow, that sounds like a big difference. If all else is equal, then that means you have more capacity with the lighter brass--so the velocity should be down a bit. I wonder if the lighter lot will hold up as well for reloading.

I was sorting some new WSM brass by weight and one case was a lot heavier. I got to looking, and it had a big brass chip curled up and smashed against the inside of the case, creating a deep crease on the inner wall near the head. From the outside it looked fine, but I bet that could've been a bad day if I hadn't found it.

Re: The lighter lot and reloading:
Surprisingly the heavier stuff developed loose pockets quickly, and the loads were not esp. hot. It could be that the alloy of that batch was a little weaker, hence the heavier cases. That is, they made them heavier to compensate.

As to case capacity and velocity, we shall see. I have only a small chrono sample on the first batch so the results may not be clear.

Forty years + of loading and I'm still learning. Especially to sweat the details and keep meticulous records.

I don't care much for Nosler lies.
I can tell you, that Federal was making the initial run of Nosler brass. I bought 2 boxes in 300WM, it was the heaviest brass I have ever come across. It was also very soft, primer pockets loosened on mid range loads. I had some Federal cases a buddy gave me, they weighed almost the same, so I sectioned them, except for the flash hole chamfer, the cases were identical.
A buddy has a later batch, we sectioned them and a Norma case, again, identical in weight and internal shape.
Now, if Nosler are NOT in cahoots with Federal/Norma, how is their brass the same?
Unless they rent dies from them, there can only be one answer.
My own 300WM Norma cases weigh 215gr on average.

Cheers.

that's been the case for years..I always load Remington brass two grs. lighter than WW brass, but still get the same velocity and POI in most of my 270s and 30-06s for instances..also in my 250-3000s..thicker brass takes less powder but combustion in smaller chamber creates more pressure and velocity...

Unless your loading max, it makes little difference. but, you should be aware in every case..A good reason to use the same brass all the time in your rifle. I like WW brass, been using it for years, but its getting very hard to come by...I am slowing switching over to PPU brass, and Im finding it to be the best brass Ive ever used, it lasts forever.