My guess is that you are talking about Jackrabbits. In Idaho they are classed the same as coyotes and they have open season all year and you can hunt them with anything.
Don' t know for sure but the same is probably true in Nevada. A quick call to a fish and game department would probably get you the info you need.
It is probably legal to hunt them with an AK-47 (caliber?)but if you are not using very fragile bullets there would be real safety issues with lots of bullets ricocheting off into the distance. I would say it would not be a good idea using solidly constructed bullets.
Lots of people hunt them here with AR-15' s in .223 but they use fragile varmint style bullets to keep the bullets from ricocheting.