I need to adjust the stock sights on my Ruger 10/22 they are a bit off. I was able to do the vertical change but left and right is a bit more difficult. I know I need to use a brass punch to drift the rear sight, but what size punch is good for this task? Will one size punch fit all future sight needs on rifles/handguns or am I better off buying a brass punch set with multiple sizes? Also should I do anything with the sights after I drift them to help them stay in place?

Buy a set. Sights will gnerally have a flat area where you will place the punch. Sometimes the area is smaller or larger, hence the set. A small hammer will also help with the small adjustments.

Good luck.

Thanks for the help MedicYeti.