Bought these MTM Cases to hold various 20 ga shotshells: buckshot and birdshot. The clear-smoke case allows you to see what's inside, and the cases stack well with ridges on tops & bottoms.
There is a removable grid on the tray that is used for 20 ga shells and it stays in place securely. The shells do move around a bit, but I use these for home storage so they aren't transported much.
I also use the 9mm and 380 Auto MTM Cases and they do a very good job as well.
Pros: Relatively Small Footprint, Stackable, Solid Lid Closure
Cons: None - Works for me.
This review was written in the old system and had content requirements that are different than reviews written today.