I am trying a number of different loads for my 280 Remington. The rifle is a magnum research built on a sako action. The twist rate is 1 to 9. I am ignorant on twist rates and get varying opinion as to what bullet weight to use and issue with lenth of bullet.
Any help is much appreciated.

Should be good all the way up to 175 gr. I dont have a 280 anymore, but I am starting to work up loads with IMR4350 and 160 gr Speer Hotcors in the 7x64.

GL

A 1-9 will let you use any 7mm bullet you want, even the heavier monometal bullets. Now you just need to decide what you will be hunting and pick a bullet constructed well enough to do the job. 168gr bullets are a great all around weight for 7mm guns. Lots af good bullets from Nosler, Barnes, and many others. I like TTSX bullets but those aren't the only good ones for sure.

Thanks for the advice and help. After a bit of testing the rifle seems to like the 160 grain Accubonds quite well.