I see quite a few posts in other threads concerning accuracy. There is a subsonic/supersonic discussion up in the 97B forum that made me think of some other factors relating to accuracy. One of the most misunderstood anomalies in handgun shooting is this one:
I was shooting 115gr bullets in my 75B with good accuracy but wanted to try a heavier bullet for better penetration and functional reliability. However, when I switched to 147gr bullets my group moved up the target by nearly 6 inches. It still groups well but now shoots high.
Why would a heavier bullet shoot higher than the lighter bullet?
Handguns recoil in a slightly different way than rifles. The relatively short gun has a tendancy to pivot on the axis of your wrist (barrel flip) thereby causing the barrel to tilt upward instead of just pushing straight back. The fact is that a heavier bullet causes a tiny bit more flip than the lighter bullet, causing the heavier bullet to print higher on the target.
This effect can be compounded by a difference in velocity. A lighter bullet will normally have a higher velocity than the heavier bullet. This means that the heavier bullet stays in the barrel a nanosecond longer than the lighter bullet therefore it's trajectory will be ever so slightly higher as the barrel is tilted higher.