On many older guns, you "drift" the sights. I have met a number of people who do not know this.
If your rifle is shooting to the right, you move the rear sight in the direction that you want the bullet to impact. Take a brass punch and hammer and tap the rear sight to the left. Fire the gun again and adjust until the bullets impact where you want them to.
If the elevation is off, you should be able to raise or lower the rear sight. I
If you cannot raise the rear sight, then you can raise the impact of the bullets by filing down the front sight. Go slowly. Remember, you move the front sight in the direction opposite of where you want the bullets to impact.
If your rear sight is not elevation adjustable and you need to lower the impact of the bullets, you may need to replace the front sight with a higher blade/bead.
I hope this helps.