I primarily use three bullets in my 280 Remington 700:
154 Hornady, 162 Hornady, and 150 Nosler Partition. The partiton narrowly gets the best accuracy. Not much differece though. Just under 1 MOA with full power loads. I like Hodgen Powders but the IMR4350 works well, too. I normlly use the 280 for Fall hunting in SD with temps generally < 32 and > 0 degrees F.
I had a 280 on a Mouser. It had too long a throat and too slow twist. It liked heavier round nose bullets best.
