re: 12 Gauge Semi-Autos

Among those choices -- the Beretta A400.

Then you still have to decide which model, bbl length, etc.

I shoot several cases throgh mine before I bother to clean it. You'll probably treat yours better, but the point is they just don't jam.

The Berettas (and probably most other guns) come with a set of shims to let you adjust the fit (drop and cast), so I wouldn't pay too much attention to which gun "off the rack" fits best.

A400 also comes with swivel studs that allow you to attach a sling. I presume most of the others you listed have swivels, too.