I bought a pre-Knockabout model (1891) in original configuration with damascus barrels. This 12 gauge has 2-5/8" chambers, which I bet was the nominal chamber length for Francotte 12's of early production. It now has long forcing cones as recommended by Sherman Bell, and I have shot many nitro loads through it.

The quality of the low end price gun is probably typical of the period. Fantastic triggers, good engraving, and decent balance... a 30" barrel gun at 6-3/4 pounds.