I had a Model 12 in 28 ga, 1935 vintage, 26" with mod choke and Simmons vent rib. My records show that it weighed 6 lb 15 oz..
It handled well and functioned perfectly. Bit heavy for a 28 gauge but still a real nice field gun.
Barrel was marked 2 7/8" chamber---I recall later models were marked 2 3/4".