Chris, A 270lb bench press is impressive for 17 years old so don’t let yourself get discouraged. You are young and have plenty of time to get big. I would recommend that you get a mindset of patience and hard work. Many people have a 90 day mentality when it comes to fitness (I want to get buff for the summer…you know guys like this i am sure). The best advice I can give is to work hard and stay consistent. Give it a couple years and you will be surprised what hard work coupled with gym time can do.