I commend you on your choice of rifle for the task. The round falls somewhere in-between a .308 and a 30 40 Krag. I suspect if brass were more commercially available it would be a much more popular cartridge amongst hunters here in the US.
I watched the video and when the guide asked you if you were shooting FMJ ammo it sounded like you said yes.

No wonder it took 3 shots to put him down and the shots punched through him like paper.

If you can afford a guided hunt like that you can afford some proper ammo for that gun.


Get yourself some proper ammo sir!