In the truck? 2 boxes. We hike in and spike camp, I keep 3 in the mag and 9 in a holder in my pack or bino harness. If I need more than 12 to fill one tag then I get to take a hike back to the truck.
This makes sense cause you seem to run out of ammo a lot on your hog adventures. Lol
That being said I also carry just a ful mag of 5-10. If for one species.