I have worked up loads for several 6.5CM and they all shot 1/4” or less at 100yards and 3/4or less at 300yards. Load for all were:
Powder- H4350
Charge- 42.0-42.5 gr.
Bullet: Horn. 143ELDX
*Note: adjust seating depth to lands. Some shot touching and some were around five thousands off.
Hope...
Depends on what your comfortable shooting. Any of the above will do what you are asking . Stay with what ya know. A lot of different calibers equals a lot of different components to make ammo. As the old saying goes “Beware of the man with one gun , he probably knows how to use it.”
Don’t reinvent tll
Don’t reinvent the wheel. Why not go with the trusted and proven 30-06?
Bullets are available at Wally World, easy to load for , and capable of taking any North American game. JS