We had trouble with CCI primers, switched to Federal and the problems disappeared. This was in caliber .38 special, and I noted that the later model .357 revolvers that some officers carried ignited them with freat uniformity. The older guns like the Model 10's and 15's were the ones having problems. I replaced some hammer springs, properly lubed the guns, in one instance removed and replaced the firing pin and in another replaced a hammer that was warped and struck the frame on the way down. Perfect ignition with CCI's. However, by that time administrators were heavily into Federals.
A few years ago Handloader magazine did a drop test and found CCI primers to be the hardest to ignite of all common brands.