I believe you are asking about a Daisy model "20th Century" BB rifle not a gun.
It all depends on the condition of the rifle and is it still working. It can be anywhere from $75 in poor condition to $400 in Very good condition, or More depending on the particular version of the rifle.
Which model, what is the condition of the BB gun or is it a BB rifle..
What condition is it in, that determines the value.
What condition is the Daisy in? This will determine the value.
Daisy made several models that year. What model are you asking about?
$15.00 to $25.00
20-50 USD
What condition is it in. That determines the value.
What condition is it in. That determines the value.
What condition is it in, That determines the value.
Daisy has a web page to help you determine the value of old BB guns. See the link below.
It's a BB Gun.
It sounds like a Daisy BB gun.