I agree with @Hellpriest1 . They are fun, but not particularly efficient in a nerf battle. If you think about it, you have to load them twice - once into the shells, then again into the blaster. But as a gimmick, it is pretty cool.
Problem is, all the Nerf® blasters like the SledgeFire and the Trilogy work like breech loaded shotguns. It wasn't until blasters like Spring Thunder that they actually worked like pump action shot guns. And you can order as many shells as you want for your Spring Thunder, so you won't be constantly scrounging for both shells AND ammo.
Shout out to GDop26 - the Model 6 is POGGERS https://www.etsy.com/listing/606780804/spring-thunder-model-6-storm-trooper