To get a good idea of how you are doing I would try going to a local IDPA (www.IDPA.com
) match. You can shoot your first match for free and all events are timed down to the hundredth of a second. All you need to shoot are your Glock, at least 2 magazines (3 is preferred), concealment holster that covers the trigger guard(no SOB holsters), and a concealment garment that covers the gun and spare magazines(eye and ear protection also required).
Most local matches go through 50 to 75 rounds and last a few hours. All kinds of skill levels are usually present. Stock Glocks are the most common gun at the matches, followed by 1911's. Shooters are scored by skill level, by gun type, by accuracy, and by time.
It's not as stressful as a real world shooting, but it is surprising how it affects your shooting when you are racing a clock and you know all your shoots are being scored.