Re: Light Strikes
What weight of trigger/what model trigger package did he buy? Some very light trigger setups often have light hammer springs, which can cause light primer strikes. He may have to either go to a heavier setup or contact Geissele about a fix.
Another possibility is if he's running a lightweight firing pin. I've seen some people who run the really light titanium pins have this issue, particularly if they are running lighter springs.
This is of course after ensuring everything is installed correctly, like ktdls7 stated. Also, take a look at the firing pin and ensure there is no deformation or damage.