Huntaway, flintlock or caplock, no difference in terms of muzzle energy. But I would surely be practicing with it first. The possibility of a hangfire is very real with a flinter compared to even a caplock. Even a slight delay may be enough to throw your sights off if you do not maintain the sight picture until it goes boom!
But that should not pose a problem if you have a good rest at your stand sight.
Good luck to you.