Air_ReeroMy guess is a latency issue because your client is having lag receiving info from the server that you hit your shot. The only problem with this is that you said you had relatively low ping so I'm not completely sure whats going on. Could be routing issues or packet loss, or maybe client lag? Have you installed anything new recently into the custom folder?
i haven't touched anything in my tf2 folder in about a year and a half, other than HUD changes.
someone who lives in the same house as me plays tf2 and doesn't have this problem.
I used to have this exact problem, I would empty my entire shotgun clip in them and half a second later everything would register later, i couldn't find a fix so I just reinstalled my os