Hello,

I had a very nice (perhaps the BEST MADE factory rifle I have had) Mannlicher-Schoenauer GK 7x64. With a great Hensoldt Diavari 1,5-6x36 scope. Mounted in a lateral Gastinne-Renette rotary mount. Truly unique, strong and very well made mount from the sixties.
I used mainly RWS H-Mantel and TIG (173 and 162/177 grs respectively). Plus my own reloads using these RWS brass and 6 boxes of 280 Remington virgin brass I bought. Only two steps to do to get 7x64 cases from those .280 Rem: 1- Pass the .280 cases in the 7x64 full length sizing die, an 2- Cut the extra length of the neck from the .280. From there, use the cases as 7x64 original ones. Never had a failure. Anyway, I anneal the necks/shoulders after two shoots.
Taking in consideration the individual rifles and cases, in my experience, the same loads can be used in both cartridges.

Good luck!

PH