.Because not only are you going to fire 100 rounds, you're going to have a TABLE to set your stuff on
Hey, I carry a table with me in 3-gun. I even have a 3-point sling for it. Doesn't everybody do this?
Look, I have 3 10rd magazines and 2 5rd magazines for my Saiga. That's 40 rounds. If I burn through all of those and there's still a threat, it's time to either run or switch to a recoilless rifle.