I’ll bring a box with me either in the case for flying or in the truck where I park. I carry a full mag plus one into the field or back country. Sometimes an full extra mag if it’s grizz country.
I usually take 20 on my belt plus another 20 in my back pack and whatever my magazine will hold, but I may pare that down to just the 20 on my belt and what's in the magazine. My problem is I want to be prepared in case the scope gets knocked around, but maybe I will pack a bore sight next time in lieu of the extra 20 rounds. I'll have to weigh those differences when it's pack time.
I reload so when going somewhere, 50 in a box. When I'm going into the field, 3 in the gun (300 wsm in small AICS magazine) and 7 in my hip belt (large AICS magazine).
Eberlestock makes a great small ammo pouch. Can go in pack, pocket or attach to belt That gets filled, usually 8-10 depending on caliber, then fill the mag.
3 in the gun, 4 in elastic loops in the bottom of my bino case and the 3 in a ziploc bag in my pack. 10 total, I can zero a rifle or replace wet bullets and still have enough left over to hunt with. I reload all my ammo, so I have 30-40 more in the truck.
I put the box in the truck and put 10 from that box in the ammo wallet I inherited from my brother-in-law. The rifle gets loaded from the wallet when I leave the truck. No rhyme or reason to the numbers other than that.
On any trip at least 2 full boxes. While actively in the field gun full, so 4, A couple on my person in cargo pant pocket or chest pocket. and 1/2 box (10) in my pack.
I have seen some strange things happen while guiding and the guy only had a gun full on them.
Example: client shot a deer low breaking front leg right where it meets the body. While we moved to get a follow up shot he fell and landed on his gun and slid down the hill on it for a few feet. Next shot he got at the deer I had no idea where he hit. next shot I saw the bullet hit like 2 feet in front of the deer. Just guessing that is where the first one hit. I told him to shoot at its ass...and he hit it in the front shoulder. If he would have missed the last shot it was like a 2 mile walk back to the truck to get more ammo.