Another possibility is changing your grip or the stocks on the gun. The way you grip the gun can make quite a difference in POI. Of course, this means developing a new gripping habit. But if your gun has thin stocks, perhaps try something bigger, or vice versa.
Some competition shooters apply putty to their grips to get the best and most natural grip, and it does affect POI. After they get it the way they want it, they replace the putty with an epoxy putty. Rather unsightly on some guns, but it could help.
My first step would be to fool with a few different loads.