I dont backpack hunt, and I always carry way to much ammo. 4 in the gun, about 8 in the stock cheek rest holder, 1 in each pant pocket, 10 more in the daypack.
To much is better than to little. My buddy and I went out for a quick peak one afternoon. He left his pack in the truck. He saw an elk and ranged it at 250. He took 3 shots and missed 3 shots. He left his spare ammo in his pack, in the truck...
He re-ranged and it was actually about 415. He hit a tree at 250 on the first range attempt and launched his only 3 rounds. Once he re-ranged because he could not figure out why he missed he realized his mistake...
We never got another shot at those 2 elk again.