I have not looked for any but I think its readily available. I had a 721 in 257 Roberts. It had a cracked stock when I got it so I replaced it with a used one and the gun shot really well. I shot one in 300 H&H that my Uncle had. He took a ton of Plains game with it plus some bigger game as well.

I just checked, Midway has Nosler Brass in 300 H&H and says Norma brass is coming soon. Better buy One DD