RE: Grand Slams in the 35 Whelen?
May not be a premium bullet but my partner uses160 GSin 280rem, it shoots them awesome. It has worked on everything he has pointed them at which includes black bear, moose, elk and deer. The bullets we have recovered were perfect mushrooms and retained 60 - 70% of there original weight...not to shabby IMHO for a standard bullet!
I however have not got them to shoot as well asothers in my 7mm rem mag.
Only one way to find out load and shoot them. I agree a lot of good bullets to choose from,best of luck.