Correct Answers:
The markings on the barrel flats reveal something unusual about this Arrieta side-by-side. It is . . . a 24-gauge with 70mm chambers
The marking “1320 bar” signifies . . . the proof-house-tested pressure, in which the “bar” is the unit of measurement
Judging from the top of the receiver, this gun’s finish is best described as . . . case-color hardened
The two “knobs” (one with screw slots) protruding from the barrel flats are . . . the barrel lumps
