sears model 21 ted williams 12 ga shotgun

Question
what size shell will this gun handle and app. what value does it have on todays market. I inherited the gun from my father in law. It is in perfect condition.
Thanks

Answer
That gun will take 2 3/4" cartridges, and I think it will also take 3" cartridges, but you need to verify the 3" by checking on the gun.  It will not take 3 1/2" cartridges.  The barrel will have lettering to show what length cartridges are acceptable.  For example, it probably says:
12 GA 2 3/4 and 3"   somewhere on the barrel.

Hope this helps!

Dave