However, how significant is this as case law outside the 5th circuit? Are other courts bound to overcome the reasoning?
No other circuit is bound by this reasoning; however, if another circuit is inclined to follow the reasoning set forth by the 5th Circuit (don't count on this; most appeals court judges are flaming, anti-gun collectivists) they can cite Emerson as support for their reasoning. But remember, all that language in Emerson that makes us feel hopeful is just dicta, (as opposed to a ruling that establishes legal precedent) so don't get too excited about all this. I'm cautiously optimistic that perhaps this case could help us regain some lost ground where the second amendment is concerned, but won't be the farm on it.