The shard that increases the crit damage of the gunwitch snipe is also increasing the damage of my gunwitch auto attack damage.  I go from 80k crits to 193k crits on my auto attacks by only swapping in that one shard(snipe crit damage one).  This allows me to pull insane dps numbers like 650k(rounded with snipe crit damage shard) when i should be doing 350k(rounded without snipe crit damage shard) with auto attacks.