I had a chance to experiment this morning with the original factory buffer spring and the H3 buffer. Also installed the new extractor and put the extractor spring in correctly (wide end in the extractor hole). Seemed to run better with pattern 1:30-2:00 in suppressed gas setting. The problem was that when inserting a new magazine after dropping the empty, the weaker original spring just did not have to oomph to drive the fresh round all the way in. I had to pull the bolt all the way back for the spring to have enough power driving the H3 buffer all the way to battery. Put the "blue" Sprinco spring back in w/H3. Pattern changed a bit - near 3:00 w/XM193 and 4:30 w/Hornady TAP SBR 75gr. Had a few failures to load new round in very rapid fire but okay otherwise. Guess I need to slow down.
Took a close look at brass and feed ramp... see pix... There is a small sharp spot on the ramps that appears to be shaving some brass. I think that sometimes the contact will deflect the round just enough to feed it at a slightly "wrong" angle. Then it will jam and bend and not seat the bolt.
https://i.imgur.com/Hltl7pj.jpg
I did a video of one round being fired, although the phone is just too slow to get what I was wanting to share (maybe with a lot better lighting - real cloudy). Maybe someone might see something I cannot. I'll make an attempt to capture a longer string of shots with a bit better lighting if I can get DW and I to sync better. She starts the camera rolling and I might be off a bit.
https://vimeo.com/362842089