Another benefit to dry firing - finding equipment issues

I've been doing dry firing and trying to keep the dot from moving in order to build solid trigger fundamentals.   Last night, due to consistent dot movement, I wondered why my finger was not able to move straight to the rear because the dot movement was the same no matter where I repositioned the trigger on my finger.

I turned the pistol (a Buckmark) sideways to watch what was happening with the execution and I noticed something new.   As my trigger moved to the rear (around the time of the shot break) the last knuckle was slightly contacting the forward part of the grip.  This changed the trigger pull from using 3 joints to just using the last one - which made the last part of the pull into a "rotational" movement.  The grip was both too fat there and did not exactly follow the curve of the trigger opening.   I changed the shape to match the opening and took some material off where the first joint was hitting, and the difference was amazing!   I'll fine tune the clearance tonight.

So an advantage of dryfiring is that I was able to find an equipment limitation which I would never have found in actual firing.   Just by way of explanation, I have very little sense of pressure and temperature in my fingers due to minor frostbite when a kid, so I had to see it to understand it.