Regarding primer sensitivity, the test that I did was with a Ruger gp100.
I had installed a reduced spring kit, which worked very well, but had ignition problems when using the pistol in double action.
Single action I had no failure to fire problems, but with double action I would get 1 or 2 rounds with failure to fire.
I then loaded up with Federal small pistol primers, and had no failures.
But, to not to have problems with CCI primers, I replaced the hammar spring with one that is a 12# spring rather than the 10#
spring. I don't have a problem now.
That's how I solved the problem. It was definitely spring related, as I did not have the problem with the original springs.
By the way, the Ruger GP100 is the easiest revolver that I ever tuned.
You could have the same type of problem with a semi when using reduced load springs, especially Like I had with my Glock 35.