Need some help for a friend.

[PvillePiper]

A couple of friends of mine are having issues with their system when they play BF4. The are both on the same internet modem. The internet is thru a DSL that gets about 6mb down and .40 up. His ping is good to the server, usually less than 50ms. Larry has more issues than Dave so I will go into detail as much as I can about Larry's system and his issue. Larry's system is as follows: Win 8.1 64 bit OS, The monitor is a\BenQ RL2460HT, CPU is i5 4670k, 8 gigs of ram, and a GTX 760. The system is on a SSD and BF4 is located on the E drive, a SSD as well.
The issue that he is having is that at times it seems like he is out of synch with the game. If a player is standing he can kill them without much issue. If the player is moving he has a very hard time killing them and usually loses the gun fight. He might get multiple hit markers and the opponent walks away without much damage and sometimes none at all. At times it seems like if a player is looking at him or shooting at him his soldier just stops and dies.
Yesterday, Dave was downloading games and while Larry was laying BF4 and Larry had a good day. Today he couldn't hardly play at all.
I have helped him set his port in BF4 to a different one than standard. My feelings is that it is and internet issue. Again, it will happen even if Dave is not on the internet and sometimes rebooting seems to help or even fix the issue.
Dave has similar issues as well but his don't seem to be quite as bad.
Any help or suggestions would be appreciated.

[flood]

pretty sure bf4's hit registration and netcode is just bad
i wouldn't have high hopes for something with 10 tickrate

[PvillePiper]

Any help or suggestions would be appreciated.

Please refresh your memory with the above quote from my original post... I realize it was very long for you to read and your attention span is was not up to the task.
The "Netcode" and hit registration issues have largely been corrected. I know of no perfect game and I know of no developer who has gone to the lengths that Dice has to correct the issues that were largely caused by EA and their desire to beat a competitors release date.
I still feel that this is an internet issue but that there maybe underlying issues in his system. Being a site that primarily focuses on lag and high frame rates I was hoping someone might offer some insites to system lag or how to pin down where the lag is coming from.
Again, any help or suggestions would be appreciated.

[flood]

well have you tried the following?

using the same computer with different internet
using a different computer on that network

system lag would be very very obvious and i doubt it's the case with that hardware. if in doubt, run with the lowest graphical settings and see whether the issues persist.

gamers love to blame their own inconsistencies on external factors and it could well be that there are no internet or system issues and that the game just works like that