Installing adjustable sights on a Beretta 92

My Father has been having some difficulty hitting the bulls-eye with his Beretta 92, he says it shoots too low. About 3 inches below his aim at 25 feet. 
At first I though the problem might not be the gun, it could be that my Father is not used to shooting the Beretta. Although he doesn't have the problem when shooting his Bersa, which uses a similar DA then SA trigger pull.  
He  had his friend try to shoot it as well, the results were the same.

I did some internet searching and found a lot of people have had the same experience. It seems the Berettas are designed to be aimed at 12 'o clock instead on on the bulls-eye.
Rather than conforming to a new way of aiming for this one gun (it is not his primary carry weapon) he asked me to try and remedy the situation. There are two ways to fix the sights, lower the front sight or raise the rear one.

Here is his model 92 Inox

The front sight is fixed and machined into the slide, so we didn't want to modify it.

The new Beretta 90-Twos and 92A1s come with a dovetailed front sight.

From what I have read, cutting a dove tail in the front of the slide of an older model 92 is not possible as there is not enough metal present.


So we decided to raise the rear sight by swapping the fixed sight for an adjustable one. Here is what the factory rear sight looks like:

I found two adjustable sights online, one from Pachmayr and one from Beretta. I always prefer using factory parts and since the price was about the same, we ordered the Beretta.

 The kit comes with the adjustable sight, a key fob adjustment tool and an Allen wrench.

 The sight has an Allen screw in the front, right above the dove tail, this is to lock the sight in place

We drifted the old sight out and drifted the new one in. We used red Loctite on the threads of the set screw.
Here is what the sight looks like installed.

I'll update this post with a range report once we get a chance to go shooting.

We have success, after a couple of rounds to dial in the windage adjustment, we put up a new target. Dad's 1st shot hit the bulls-eye from 10 yards! He was very pleased. We each shot a 5 round string. I was able to put two more on the bulls-eye overlapping his. Out of the 10 shots we only had one flyer outside of the black.

Here is the target:

This solution may not be for everyone. Dad does not use this as his carry weapon, he bought it for target shooting and perhaps home defense. The adjustable sight is of good quality and it probably would survive repeated holstering just fine, but they may tend to get hung up on clothing.