I'm not sure if you want to solve your issue, or just bitch about it.
I can help you solve it.
The Elftmann trigger is very unique in that it has a "half-cocked" position.
YOUR trigger is not catching on the disconnector after firing, and is getting caught on the half-cocked position. THIS is the cause of your "very light primer strikes." You are firing from the half-cocked position. Not enough force to do much.
Now,ONE of TWO things is causing this. Only one of two... Nothing else...
1. Poor trigger follow-through. Jerking the trigger, slapping the trigger, etc. Not holding it fully to the rear after firing, and through the recoil impulse.
2. Gross misadjustment of the trigger assembly. The disconnector isn't even given the change of doing it's job, due to the trigger adjustment.
Now, I know you've stated your Marine Corps Armorer 2112 qualifications, and I know you stated something about correct follow-through. That leaves misadjustment...
Did you fuk with this trigger's adjustments in ANY way prior to installation? Or did you just drop it in and go?...