What is the minimum amount of powder you would use with the above projectile to hunt Elk?

My Knight Disc Extreme 50 Cal shoots them very well with 65 Grains ( Volume ) of T7 3F. The groups opened up at 70, however, I was messing around with not swabbing, etc. I did not try a load greater than 70.

Also, any guesses on FPS leaving the muzzle with 65 grains?

Thanks,