So I keep noticing shells flying outside the reticle and it seems the issue is the aftershot bloom and gun raising are actually happening a split second before “firing,” causing the accuracy to go wonky. That is you fire and the aftershot effects are happening too early.
When I slow these shots down frame by frame, you see the bloom and gun raise just a few frames before the gun firing, which is leading to wonky accuracy. Photos below. Notice in particular the spread in red with the gun saying it is still “ready.”