Need a good rifle in the right caliber. Remington 700.
.338 Win Mag
.338 Remington Ultra Mag
.375 H&H Mag
.375 Remington Ultra Mag
8mm Remington Mag
But he is in Canada. I’m not sure he can own a rifle. The .375 H&H or the Ultra Mag would get my vote. BTW not for casual plinking. These are real shoulder thumpers.
12 gauge running .50 caliber sabot slugs should do the job.