I have one of the older LnL APs - I'm not sure exactly when the updates were made, but I know that mine came with the (for me) totally non-functional ejection wire, which I've since changed to the newer EZject system and also with a single rotor drum (inexplicably, the rifle rotor, which makes no sense at all), so I subsequently purchased the pistol rotor, which is what gets used about 90% of the time. I'm not aware of any change in the basic priming mechanism, but I know I had to tinker with mine (primarily adjusting the vertical tube that the carriage wheel rides on) a bit to get it working properly but, once having done that, it's been fine ever since.