Why would Nosler make two 257 bullets so close in weight? For slower twists?

Perry

I would think that you could drive the 115 a bit faster than the 120's, might make a difference to some.
I know for me the 117 Sierra's are pin point accurate in my 257 Roberts, the 120 Partitions are not, I don't know if it is the change in weight or shape that is the difference.
I believe many manufacturers also make many bullets in .243 and .257 that are within 5 grains.
70, 75, 80, 85, 87, 90, 95, 100, 105, 110, 115, 117, 120.

More choices the better if you are trying to find the sweet spot...

My .25-06 shoots very well with the 115 gr. partition but not nearly as well with the 120 gr. I do not know why there is that much difference between the 2 bullets. My rifle is a Rem. 700 Classic with the factory barrel. The 115 gr. has done well on quite a few mule deer and antelope. Two friends used it and each made 1-shot kills on cow elk. The 100 gr. partition also shoots well in my rifle and did a good job on a couple of antelope but I now use the 115 gr. for everything.

Back in the day I had a German Weatherby 257 that had a 1 - 12" twist. The loading manual listed loads for 115gr but indicated that the twist was too slow for the 120. A 257 Roberts had a 1 - 10" twist that would stabilize the 120gr but within 300 yards the 115gbr had a better trajectory, so I don't know why Nosler made a 120 gr other than to meet the competition (Speer, sierra, Hornady).

Nobler does the same thing in .24" caliber. They make both a 95-grain Partition and a 100-grain Partition. It probably all has to do with twist rates of available rifles.

Who knows, maybe customer demand..or perhaps for the 250-3000 wherein the 115 doesn't take up the powder space so much...

That's why I like the 110 gr. Accubond in both the 257 and 250-3000..Ive shot a few deer and an elk or two with this load in the 250 so Im sure it would be a dandy elk load if one is careful and doesn't try to stretch the sting on the elk..