you young ones are so spoiled. back in my day quake servers ran on 24 ticks....
having said this there are a few things you can do client side to somewhat improve hsr.
1. 60 fps locks and vsync are bad. if you do this your driver is probably buffering prerendered frames and costing you an extra ~20ms of lag.
2. check the rendering latency of your monitor. on many 60 hz monitors you are getting significant extra lag, like 30 ms or more.
3. check your nvidia or ati drivers to see the number of prerendered frames. if it's more than 1 you are costing yourself about an extra 10 ms.
between the above 3 the world you see on your monitor has about 100 ms of extra lag than what your ping shows and what the server thinks you have.
then if you use lots of postprocessing, high quality tetextures, etc, your adding additional measurable delays.
after you've killed off delays in the graphics chain you can move on to os and nic settings. things like background intelligent file transfer, Windows search indexing, nic jumbo frames and flow control can all add significant delays.
one way you can measure measure some more f these delays is to run a dpc latency checker on your system. you'll see that most of the time its hovering around 100 ms. you have to carefully configure your system to get it below 50.
so, in addition to the Internet, which is the ping you see on your score tab, the server, your system is also introducing significant delays that the server can't predict or measure.
thus the reality you see is offset from the reality the server sees by your ping + 50 to 300 ms, with large unpredictable fluctuations if you are not careful in managing Windows background processes and cpu power saving state, so of course things will seem weird or unreliable at times.