Sounds a bit off to me.

There's .005" maximum difference between brass neck thickness as witnessed on loaded ammo - yes - .025" per side - not much for a hunting rifle - closer to a gopher gun.

The .438" case looks to need turning. The rest are pretty good but still tighter than normal, I think.

Did you measure in several spots around the case mouths? Brass is rarely closer than .0015 even, even in match brass.

Sounds as if the chamber is too tight for shooting normally larger diameter cast bullets, if .410's are snug.

Are you able to neck turn a couple thou. from the necks to allow .412" cast? If cast bullets are a push fit + a tich tighter, that's OK and not having to size the brass would be nice when shooting cast.

You might try .410" cast bullets of something like a 12 brinel. You might find the shoot well if not much harder than that. The softer bullet is more likely to obtruate and seal perfectly and shoot exceptionally well, whereas a groove diameter hard bullet rarely shoots well & causes leading due to gas cutting.