I just thought I would share this. I got to the range yesterday for a bit of shooting & ran some Speer 160gr Nitrex ammo through my mew .280. I was looking for a benchmark 160gr load to work towards a good hunting handload.
I was getting consistant (3) shot groups under 3/4" w/ muzzle vel. avg. right at 2900fps (23" thin PacNor bbl., 80deg. afternoon). This seems very fast as Speer shows 2850fps in their lit. Anyone else try this ammo? I had shot some of the .375 GS in my number one a few years ago, & while it also was quite fast, accuracy was poor. Maybe I don't need to work up a hunting handload?

I'm not surprised your Pac-Nor barreled .280 shot well. Mine certainly does.
Sounds like good accurate ammo. However, the GS bullet tends to loose it's front core in testing. I'd have more faith in a different premium bullet if you need one. My .280 loves the 120 gr. Barnes XBT. E

The .30-06 loadings shoot well in my M-70, This M-70 was reworked some by Carolina Precision Rifles. Yea its got a Schiendler barrel and its just about perfect. 165 gr Nitrex loads will group less than 3/4 of an inch at 200 yards. Works great on Deer and Carabou too. I think there 7 x 64 loadings will shoot well in my Sako too. Its real good ammo.