Boito Large frame small frame.

[Buster95]

Boito (Stoeger) side by side shotguns comes with small and large frames, so I suppose large frames are used for 12 and 16 gauge?

 

[Falconflyer]

They only list 12, 20, 28 and .410 on their website so I'd think large frame for 12 and small for the rest. It's possible that the 20 g might be on the large frame but I doubt it.