Re: 280 out to 1000 yards
Just a curiosity, but I seem to remember that the 280 is a 7mm (284) bullet and meant to compete with the 284 win? It's based on the 30-06 necked to a 7mm if memory from Hunter's Safety serves me right (from 15 yars ago).
If that's the case, then the heavy 7mm VLD's would certainly get you there and I think you should get some really good velocities out of them with all that case capacity.
I might be talking out of my ass on the case dimensions, but you can easily reach 1k with a 7mm-06 if that's indeed what the 280 is.