Just get a waist shotshell pouch.
For me, a vest with 100+ shells is way too bulky.
I just toss a box of 25shells into my pouch and Im good to go for clays. I can fit 2 boxes but I prefer one.
But for hunting purposes, a vest might do you good as you can hold a ton of shells in it and also other accessories like your phone, knife, chokes, etc.