Sadly, if you have a gut on ya, it will stick out past your chest if you bind it well.
My gut sticks out farther than my chest when I bind (which is pretty much every waking hour) and I got a proper underworks binder.
I don't rightly care if I look like I have a little extra weight on me, as long as I look like a bloke with a little extra weight on "him".
'Course the best advice I can give you isn't binding techniques, but to go through what you eat in a day, cut out things that are low on nutrition and high on salts, sugars and fats, and start walking more and eventually getting into a good, solid, exercise routine.
Not only will that help with the gut, but it will help with the chest area. After all, tits contain a lot of fat.
(and for the record... I'm working on just that myself. )