there is slide release on right hang side small button push this in then pull slide backwards toward you if this dose not work take to a local gun smith
Most likely, the pump shotgun you have is a model 10. Uncheckered wood, grooved slide, value is from 150 to 300 dollars.
July 10, 1902 Patent application was filed on a pump action shotgun that would become the Stevens Model 520.
A pump shotgun.
1913
1920
1913
Yes, I just bought one
Made in 1908
Early 1909
it is a 410 ga pump shotgun
your winchester model 1200 shotgun has a pump action.
10-500 usd