As per all .22s,try as many different brands of .22 ammo as you can. You will find one that groups the best,then dial in the sights.
I had a .22 6.5" bbl.N.F.dual cylinders,I bought,with the box,for $125 back in 1988,slightly used. Ironically,some cheap,lead .22s shot the best(probably expanded to fit the bore better). Traded it even up,for a New Service .38 Special,in 1991. While the N.S. is certainly worth more today,I can't believe how much the .22 Colt S.A.A.s have gone up in value;should've hung onto my Frontier Scout and Peacemaker a while longer!! But just didn't like the feel of the 7/8ths size Colts.