Pre-14.6, when a weapon scored a successful hit, sometimes the damage from this hit was not registered until the second graphical hit landed (during the cooldown phase of the weap). In these instances, the first hit would graphically be a miss, but one would not get the "you tried to hit Real Mean Bob but missed message" because the skill roll was successful, it was basically just a timing issue. The split second delay also frankly didnt matter unless you threw a nano after the first graphical shot (which showed as a miss) but before the second shot graphically landed as a hit--if you did, the damage for the shot was not applied and was lost.
I was messing around with an alt, and I noticed that the "first" shot (now the only shot) still sometimes graphically misses (but I didn't get a special "you missed" message), but because the second shot graphic never occurs, the damage for the successfully rolled hit never happens. That is to say, I did not see a miss message, nor did I see a "you hit <target> for x damage" message, nor did the mobs life bar move.
My first thought was that it was a simple LOS issue because I was doing root and shoot, so I stopped doing roots or forcing any mob movement and the problem persisted. My next thought was just bad sync on a reload message (especially since I've repeatedly seen "reloading weapon, you hit for x damage, weapon reloaded" already) so I started watching my ammo and this was not the problem.
I can't absolutely confirm that the damage is not being inflicted, only that I'm not getting a message about it and that the life bar is not moving (of course, they're misreporting so bad that doesn't say much). Has anyone else who can understand what I'm talking about seen this problem? Maybe I'm just really tired :P.