A SxS in useable but not like-new condition will bring between $100 and $250. A 20 gauge or .410 will be in the mid to upper part of that range and a 12 or 16 gauge in the lower to middle part.
You have a Stevens 311
Numrich Arms has parts for the 311
100-300 USD
I have seen a 311 .410 side by side for $300.00, but I think they are worth alot more than this in good condition. However I have not been able to come up with a firm value.
$250-$350.
I too have a Ranger .410 sxs hamerless shotgun. I believe it to be made by Stevens. Possibly a model 311.
value of stevens 410 58b
The Stevens 311's range in book value from $245 (100% condition) to $115 (60% condition). Add 30% for the .410 bore.
Just sold one for $750.00/ like new
These shotguns range in price from 130-250 dollars depending on condition and a good bore.
Try e-gunparts.com
I'm pretty sure if you lay it side by side with a Stevens 5000, 5100, and 311 you'll find it is identical to one of them. Useable Stevens doubles sell for $150 to $200 and some people will pay as much as twice that for the 410s.