1 .70 calibre ball isn't deadly enough?
Guys in the states use .45 RB's on them from their flinters.
The odd guy uses his .62 smoothbore, usually with a .590" to .600" round ball & only 80gbr. 2F or less.

Buddy of mine up here has shot a LOT of moose with his .75 cal. Sporting rifle.
He now uses a .715" WW ball and .030" patch with 120gr. of 2F GOEX.
He started off using 200gr.2F and reduced his charge, year after year trying to get a ball to stay inside a moose. When he had dropped his load to 120gr., he succeeded in keeping a ball inside the moose.
Sounds like a lightly recoiling (respectively) pig load to me.