Hi,
I’m looking for some tips or advises on loading and shooting the Kodiak double rifle in .58 cal.

I get a Pedersoli Kodiak rifle 10 days ago and only shoot about 20 times with a charge of 80gn FFFg (the only powder I can get.). Do not like the sights on this rifle, I can not shoot accurately with them.
For what I can see, round ball are crossing about 20 meters as bullets from right barrel hit to the left side of the group and bullets from the left barrel on the right, with left barrel a little higher than right; that is at 25 metres and at 50 meters.
Trying the 440 gn Lee R.E.A.L. bullets make tighter groups (3.4” and 3.8”) also crossing, 4” between centres.
What to do to get the groups together?
Classically I would have to reduce powder charge but 60-70gns is a low power load for a .58” cal. I can also use a heavier bullet but the only heavier bullet I can get is the Minnie, not a good idea from a double IMHO.

I know that this can be considered heretic, have anyone put a scope on a Kodiak?

Thanks
Martin