Get ready guys, this one is going to be along one...but systematically eliminating variables is the only way i know how to troubleshoot, so here goes.
Couldn't stop thinking about what the issue could be with this action, so i figured i'd come 'work from home' for the rest of the day, and get down to serious business. Here are the details.
1. Disassembled the firing assembly from the bolt body, cleaning both well. CLP'd the spring/pin, and Frog-lubed the caming portion just below the bolt shroud. Sorry if i got the terminology mixed up. Figured a good cleaning/lube is a great place to start.
2. Thought that possibly my once fired ammo could have stretched too much, so decided to check headspacing. Since i'm also new to reloading for this rifle, i followed this video:
https://youtu.be/ldtbsym650k Took the firing assembly back out of the bolt body and confirmed that my FL sizer / headspacing is spot on...bolt handle 'floats' up and down with the round in the chamber. RESOLVED.
3. While testing the headspacing, I noticed that it was very difficult to get the round to seat in the chamber during the first push, but if i backed the bolt out 1/3 and sent it back into the chamber, it was like butter. after further investigation, i noticed that the extractor spring was so tight that it was causing the rim of the cartridge to not enter the bolt face easily. I spent a few minutes tuning the extractor spring, and boom 100x better. RESOLVED.
4. Moved on and reassembled my bolt. Loaded up 5 rounds of sized brass w/o primers, and started testing. Noticed that the bolt seemed to be scraping my AIAW magazine some. Magazines are firmly engaged in my DBM after I trimmed the mag catch/latch when i first installed it. Switched to my 2nd AIAW magazine to test that one, and boom, no more scraping. Bolt slides easily over the magazine. looks like I'll need to sand down the lips on one of my mags. RESOLVED.
End result is that I've test cycled 100 rounds and while it doesn't feel 100% smooth (as a custom action should feel), it feels 100x more reliable to cycle rounds that it did before. I'd say it was a productive 'work' day.
I just want to offer my continued thanks to everyone that keeps offering advice and encouragement...This is such a great community to be a part of!