If your newspaper won't list firearms, you might be able to slip one under the radar because if they are antigun it is likely they don't know squat about guns anyhow. here's how...

ATV for sale. Model 7400 like new, only driven a few miles. 3006 cc engine. phone #555-5555.

It will be in the section of the classifieds that a sportman might look at and your targeted customer will know what you are talking about.