I have a buddy with a Mini 14 and we bring it out shooting periodically. Its very accurate and functions essentially the same as an AR. It also has nice built-in iron sights so if you grab it to chase something in your yard it is easy to shoulder and shoot quickly.
Last year we had a bobcat that stuck around our property and killed several chickens. I only saw it once but I kept my AR handy in case that little shit ever came back.
A 5.56 caliber will have no trouble with a bobcat, so a Ruger Mini 14 or other 5.56/.223 caliber (AR-15, etc.) would be my pick.
5.56 is my top choice because of its low cost, accuracy, and for the following: the round (in my opinion) is good for home defense because with such high velocity, the bullet tumbles after it makes impact. So if you end up shooting a bobcat, cougar, or Bigfoot, the bullet will not be nearly as lethal to anything that may lie beyond what you are shooting at (compared to a larger caliber with less velocity like a shotgun slug).
Scaring one away is a lot different than stopping a bobcat that is about to attack something or someone.. I'm assuming that is why he asked for a firearm recommendation.
Bobcats aren't really a concern to grown men... One time when we were developing my parents property I was sitting on my dads tailgate eating fried chicken and out of nowhere a bobcat was less than 40 feet from us, just sitting and staring. He was pretty chill actually, even though I almost shat my pants having never seen one before. But nonetheless it was almost no concern to us as it's unlikely that one would attack an adult. The dangerous situation is when a bobcat becomes interested in your pets, then becomes a threat. Even if you scare one off it may be back or even might stay around for a long period of time knowing he has a food source. As I said I lost quite a few chickens to one last summer and also lost our cat.