Nice group Jon... Yea, you need a higher front sight.

Here's what I would do... fold a short piece of black electrical tape onto the front sight blade making sure it sticks up higher than the existing blade height by 1/8" or more. Shoot the pistol with the same load and at the same distance. If you're hitting low, use scissors and trim a little bit off the top of the tape.
Continue the process until you get it hitting where you want then measure the height from the flat of the barrel to the top of the tape. That will tell you exactly what you need for height of whatever front sight you decide to use.

BPS