I noticed this last week and again to-night at my club while shooting with a fairly new magazine. Every 3rd CCI-SV bullet would not fire until I removed it and reloaded it again. This was in my M46 which surprises me as normally this gun works flawlessly. The magazine ejects fine with No hangup problems of any kind or signs of wear on either side. Probably time for a cleaning I suspect. I usually do both at the same time while I have the cleaning kits out. The gun shot better then I did. One of them shakey nights for a old guy. That's me of course. I had fun tho. Any night shooting is a great night.