I would think a fired case shouldn't be that hard to eject by hand? You could try polishing the chamber, BCG, and raceways, so there was less friction, I use Flitz metal polish on my bolt guns and it smooths them out quite nicely.
I agree with grayfox about the barrel harmonics try some groups off sand bags without touching the barrel, rest on the mag well essentialy.
I agree with grayfox about the barrel harmonics try some groups off sand bags without touching the barrel, rest on the mag well essentialy.