You just need to persist with learning to shoot the gun better. When I got my 4 inch barrel "The Earl" my groups were all over the place to the point of not being able to call the results "groups" at all. As I learned to hold the gun and to work the trigger better my results sharpened up. I can now do 5 shot group of 2 inch diameter at about 12 yards on a pretty consistent basis with the odd 1.5 inch group. But it took a good 300 rounds of practice to get there. My issues were the trouble and not the gun itself at all.
Stinger, someone up higher told you want a dovetail sight is. It's the manner that the sight is mounted to the gun. If your gun has a dovetail sight you can easily see this by looking at the sight from the side. The base of the sight where it fits into the barrel or frame will have ends that slope inwards so it traps the sight into the barrel or frame due to the taper of the front and back of the sight's base.
In fact in this picture of the 4 inch Mini Master from NAA's site I can clearly see that both the front and rear sights are dovetailed. You can see how the base of both where they slip into the matching tracks on the gun are sloped inward to lock the sights in place.
View attachment 514632
So if you can clamp the barrel or frame into a vise with suitably padded jaws to avoid scuffs or scratches and use a brass or aluminium pin punch you can tap one or the other from side to side. But first check that there is no sign of a locking pin or screw. Most dovetail base sights are held in by a friction fit but some use a locking set screw and others not intended to be moved use a locating pin. More likely the front is the one to move for windage as you run much less risk of damage to the height adjuster mechanism of the rear sight.
Just be sure that it's not your grip that is producing the windage issue. If my The Earl experience is anything to go by they do a pretty good job of aligning the sights at the factory. It may just be that your grip and how you pull the trigger needs a bit of work.
In my case I use the hard point of the first joint of my finger as the spot to push the trigger. Testing with empty cases and some dry firing showed me that pulling the trigger with that spot of my finger produced the least kick in the sight picture when the hammer dropped. Try some dry firing with empties in place and see if your own sight picture jumps to the sides at all as the hammer kicks. If it does then it'll pull the bullets to the side as well. Adjust your trigger finger untill you don't get any sideways jump at hammer fall.
Good luck and enjoy a great little gun. I know that my own NAA really makes me smile when I shoot it.