winchester model 24 double barrel 16 ga with 20 ga. inserts 

Winchester manufactured the Model 24 from December 1938 through December 1959, It was specifically designed as a low cost gun to compete with Stevens/Savage 300 series double barrel shotguns  The Model 24 is a true hammerless gun, as opposed to having concealed hammers like most double guns, since it is striker fired. It was produced only as a field grade gun with blued receiver and barrels, wide 7/16" raised solid rib, uncheckered black walnut stock with lacquer finish, semi-pistol grip (a straight hand stock could be ordered), double triggers, and spring powered extractors that elevated the shells when the gun was opened. Available gauges were 12, 16, and 20, with 12 gauge being the most common. small chip out of stock plate