Well at this point all I can say is we're here for you and we'll get this thing running one way or another. Wiser folks than me will be along but I'm not getting the mags not seating unless the trigger is pulled. Rack the slide, insert mag and no go? Pulling the trigger does nothing to change the way the mag and the top round are hitting the bottom of the slide.
It's much easier to lock the slide back, insert the mag and then release the slide as you say you were doing. After a bit there should be no issue just pulling and releasing the slide as long as you don't ride the slide and let it go with full force.
The mags do take some effort to lock in properly and this could be part of the issue.
Apparently there's a little extra space in the 6rd mag that lets the cartridges move down a bit to allow seating it when the slide is in battery.
I'm perplexed at this point and shall ponder some. The smarter fella's should be along before you know it.
Glad you found us.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."