Nothing wrong with buying a few boxes of ammo, but you should look at taking the NRA basic reloading class. You can get an inexpensive press and load and get exactly what you want performance wise and never be out of ammo. So you can settle on a couple rounds (target and hunting) and never deal with looking for the same loaded ammunition and rezeroing for "whats available", etc.
There are always used reloading setups available through this forum or CL, the NRA course is a good overview with enthusiasts. Save your brass from the 120g Amax, you'll reload it at some point. Those AMaxes shoot mighty fine in my .260, I'll bet they do well in your 6.5