I had taken a trip down to Nevada to shoot with a buddy. When I got down there, I was getting misfires in my 223 bolt action.
It wasn't until I got home that I figured out the problem- headspace. The sizing die I was using got a build up of lube and other crud, and was pushing the shoulder back too far when sizing. I now clean the die more often and use a Hornady case gauge to confirm case dimensions.