i would remove the rear sight and run a file evenly across the sight blade. do not open the notch in it, and do not allow the file to remove more material from the rearward side of the blade.....because it will allow more light to be reflected into your eye. if anything, taper the top edge of the blade slightly downward toward the front of the revolver. obviously the left and right sides of the blade must be kept even / level.
this will lower your point of aim with the sight screwed down all the way.
heavier bullets will oftentimes shoot higher than lighter bullets do .... because of the increased barrel time allowing recoil to raise the muzzle higher.
remember, too, with a handgun that a consistent grip position and grip strength (how tight you hold onto the revolver) is very important to consistent results.
lastly: a Ruger is generally an accurate piece. if you have trouble with 240 gr' projectiles and lighter, try using IMR 4227 as your propellant (or even IMR's "Hi Skor 800-X"). try a mild primer like the CCI standard large pistol primer (#300), with a reasonably firm crimp in Remington cases.
i would shy away from H-110 and Win-296 with projectiles weighing less than 240 grains anyway. they are relatively 'slow' (as far as pistol-propellants go) and require magnum primers and a very firm crimp to give consistent ignition, with projectile weight still being an important part of the equation with those two propellants.
take care,
ss'
