525 gr LFNGC bullet with 48 gr IMR 4198 at 1550 to 1600 fps. That is a light load for 50 AK so you can load it heavier, but 1550 fps with 50 cal 525 gr hardcast will handle anything in North America with ease. Same load was about 1750 fps in my 20 inch Marlin. I really don't like to push hard casts over that because pentitration suffers.
I always wanted to take my Marlin to Africa, but planned on punch bullets for that job that can be loaded to higher velocities.