Originally Posted By: Geo. Newbern
I wonder if there is a significant pressure problem with shooting a 2.75" 1oz. rifled slug (non-sabot) in my circa 1914 Sauer 12ga X.43 Mauser Cape Gun. The shotgun barrel has a 2.5" chamber


Yes, there is big problem. Slug will cut a piece of plastic case, when you fire 2.75" slug ammo in 2.5" chamber.
Can't say about pressure, but nothing good to shoot factory loaded slug ammo in 1914 old gun. One way to load ammo yourself.

Geno.