Hi.
The ratio seems a lot better here in SA, as a lot of guys seem to have pretty well regulated guns!
Here they are sold as unregulated however, not as regulated at 75 yards like I have seen them on Cabelas in the "States".

Mine was middle of the road! At forty yards the barrels shoot a dispersion of about an inch laterally, but three to four inches vertically. Not really good enough for hunting!

I worked on it for a while, and finally got the lateral dispersion sorted as follows.

In the right barrel i load a 590 grain modified minie bullet, chased by 100 grains of our local sub powder (not prefferred, but much easier to lay hands on). In the left barrel I load a 515 grain modified plains bullet (called the gamestalker, and manafactured and marketed by a company called Bushveld Muzzle Loading Supplies) also with 100 grains of powder. These shoot to exactly the same poi vertically, and group better than I can hold at 40 yards.

NB - the side by side double is not really intended for 100 metres, especially with the express style sights - I limit shots to about eighty yards! after all, thats the challenge of using a ML.

We in SA have no separate season for ML or conventional like they do in the "States" so the choice of using a ML is purely that - a choice!

My first hog with my double!