Well, the case starts out ahead....the USSC would have to overturn the DC Court of Appeals to rule disfavorably.
Second, if the Miller case is revisited, it can easily be demonstrated that a short-barrel shotgun does indeed have military uses (trench clearing, for example, as was used in Vietnam).
Third, I think it will be difficult for the USSC to come to a narrow decision on this. The only plausible narrow decision is that DC is not a state. I can’t see that happening.
It all comes down to Justice Kennedy. And he’s been right-leaning lately.
The key will be whether or not they consider the “unorganized” militia in the ruling. I don’t like the tightly defined question they are going to answer.