Finally got an update for y'all, though just barely thanks to all this rain we've been getting lately.
I got a day off, so I soaked my bcg in about a quart of Mobil1 full syn 0w-50 when I got home from work last night. Before I set up to shoot, I took the bolt out and wiped off the face and lugs, let the carrier drip dry(ish), then re-assembled the bcg and rifle. I made sure to coat some more 0w-50 on the bcg's rails before it went back in the upper. Once I checked that the gas block was fully open I loaded up.
I started with 1 round once again, but this time the bolt had full travel, ejected the spent brass, and locked back. So I loaded 3 more and tried again. Everything was nice and smooth, and the bolt locked back after the last shot. I think it's safe to say she functions now :)
I will say, though, that I'm hitting waaaaay low left, as you can see here (I was aiming @ top right, center @ 100yd):
In my rifle's defense, I was wore out after getting everything set up and walking almost 800 yards back and forth in the damnnear 100% humidity, and I rushed the last 3 shots to try and beat the rain. Oh yeah, and this was my redneck bench setup today:
One thing I was surprised about was how far my brass was flying. I had a nice, neat "pile" about 8ft to my 5 o'clock, and every casing had a dent in almost the same spot where they bounced off the brass deflector on the upper, which also had a good bit of fine brass powder on it. I can't believe it, but I already need to turn down the gas a little bit, even with how tight everything still is. Go figure.
Weather-permitting, I'll continue the break-in tomorrow.