Picked up one of the All Weather Hawkeye .280 Remington rifles a while back.
I've worked up several loads that work great. This one is my favorite, 140g North Fork, H4831SC, 2942fps. That is a 7mm RM with the same bullet on the left, .280 on the right. Same powder charge boosts a 140g AB to 2901fps. A half grain less powder pushes a 140g TTSX to 2928fps. All are very accurate.
While North Fork bullets are still available, this particular version is not. Mike Brady sent me a bag full of these prototypes but they never went into full production and the new North Fork owners don't offer it either. Not that I'd worry - the standard North Fork SS work awesome. I use the 7mm 160g, 165g and 180g in ,30 cal and 350g in my .45-70.