To raise the point of aim you need to shorten the front sight or raise the rear sight. But to shoot that much low at only 10 yards by the time you shorten the front there not only won't be anything left of the front sight but you'll be about a 1/4 inch into the slide be anything left..... 
A quick CAD sketch based on a 7 inch sight to sight baseline and assuming you're accurate about the 10 yards and 12 inchs I get a number of 0.23 inches that you'd need to file down the front sight. They aren't that high to begin with I suspect.
So, what's going on here? First off I'd suggest you go back and this time use your gear box and a pad or a sandbag or some other firm bench rest setup to cut out any issues with how you're holding the gun and how you may or may not be influencing it. If you look up the Shooter's wheel http://www.bullseyepistol.com/training.htm it has a bunch of possible options. An anticipatory flinch will often result in the pistol shooting that low. Using a rest that you can support the underside of the frame with will help in eliminating the shooter's input from any issues. Now and then for some reason I'll still flinch and when it happens the shot goes low.
A quick CAD sketch based on a 7 inch sight to sight baseline and assuming you're accurate about the 10 yards and 12 inchs I get a number of 0.23 inches that you'd need to file down the front sight. They aren't that high to begin with I suspect.
So, what's going on here? First off I'd suggest you go back and this time use your gear box and a pad or a sandbag or some other firm bench rest setup to cut out any issues with how you're holding the gun and how you may or may not be influencing it. If you look up the Shooter's wheel http://www.bullseyepistol.com/training.htm it has a bunch of possible options. An anticipatory flinch will often result in the pistol shooting that low. Using a rest that you can support the underside of the frame with will help in eliminating the shooter's input from any issues. Now and then for some reason I'll still flinch and when it happens the shot goes low.