Here’s a good article covering failure of a round to go off due to cycling in a gun.
http://boloreport.com/officer-safety-ammunition-cycling-and-failure-to-fire
The misfired round, which had a full firing pin strike, was collected and was later sent to the manufacturer for analysis. Their analysis showed the following: “.the cause of the misfire was determined to be from the primer mix being knocked out of the primer when the round was cycled through the firearm multiple times”. We also sent an additional 2,000 rounds of the Winchester 9mm duty ammunition to the manufacturer. All 2,000 rounds were successfully fired.