Are these all Nassarius snails?

[patrck17]

So I have a couple similar looking snails but some seem to be larger and darker than the others. The bigger ones roam about more actively and smaller lighter ones seem to only come out when food is added.

I assumed these were younger vs adult. But now I’m not sure.

 

[Gumbies R Us]

@ISpeakForTheSeas

 

[fishguy242]

Dove snails ?possible whelks ?