Try going to a gun show. Look at the guns closely. If they are well maintained, clean, they will probably be okay and not dysfunctional in any way.

It' s going to be tough finding a new rifle for 300.00 simply because a decent scope and rings/bases are going to run the price tag up another 200.00 or more.

You might find a Remington ADL for around that. They have iron sights and don' t have to have a scope.