I am looking to get a rifle for self defense in the event things go south. I own a .223 but I am looking for something that packs a little more of a punch while also being relatively budget friendly. My first thought was 7.62x39 but I am not overly interested in the AK format. The 300 blackout is similar in ballistics but fits the AR format better, which is my preference. My knowledge for firearms could be better, so I am wondering what people on this site would suggest. I am open to most platforms but prefer a good rail system for easy modifications. Caliber/gun suggestions?