Have just started reloading and went to the range today with my loads for the first time. I had several rounds that didn't fire. The firing pin hit the primer just as it should and nothing happened. When I took them apart I found that the powder had clumped and had a yellow tint to it where it was touching the brass. Most of the other rounds (I had 50 total) paused briefly after the firing pin hit the primer before firing. It paused just long enough I could hear the click of the firing pin before it fired, but still less than 1 second. I have never had that happen before with any firearm. Does anyone have an idea on my problem? I'm hoping I can improve my reloading success rate.