H3 buffer and still overgassed?

I recently completed my budget 450BM, now it's time to upgrade and tune. Generic mil spec lower, BCA 18" upper, mid length gas system, SMB H3.

The casings are ejecting at the 2 o'clock position even with H3 buffer, except sub sonic which eject but don't feed. I don't plan on using sub sonic, but I was curious about them.

I am thinking an adjustable gas block would be a smart upgrade. Maybe getting this thing to cycle properly will also reduce the recoil a bit. Still less than my .338 RUM though.