Hi Gunny,
One of the clinics we attended many years back was conducted by a nationally ranked 2700/Bullseye Distinguished Pistol Shot. That was back in the days when men were men and female shooters were scarce. We shot real service pistols of the .45 ACP persuasion one handed. He stated at the time that if he called a good shot and saw his brass eject, he knew it was a good shot before he spotted it.
For the problem you describe, even if it isn't a true, readable flinch that might or might not be masked by live firing you might try the following. (We usually did have the luxury of using coach/shooter scenarios.)
1. Lots and lots of dry fire exercises with real concentration on each shot/snap. Just like you were firing a 50 yard slow fire portion of an EIC NMC for your last leg points.
Concentrate on what your front sight does when the hammer falls.
2. Ball and dummy drills where you load inert rounds interspersed with ball rounds. To accomplish this by yourself mix rounds and load by feel. (not looking at them or your magazine.) The other method works best with an assistant or coach. Have them "load" the weapon one round at a time randomly between live and an MT chamber.
3. Concentrate on follow through thinking about holding your pistol steady and the sights aligned on your target. This lessens the natural impulse to blink or jerk/flinch for some folks.
Hope you can use some of this. Don