Hi, I own my own modded server and my friend can not reload his gun, it does the animation but it does not put bullets in the gun. I tried reinstalling the server and he tried verifying his in game files. Any clues on how to fix this?

Does your server or friend have any network issues? It may be also anti cheat doing that, I suppose there should be a setting to disable fast reload or whatever it detects it as.

The server and he have a good connection
I have no anticheat because it is a private server

Game has its own anti cheat I mean.

How can I disable the fast reload anticheat?

I had the same issue when my computer used to have low performance (bad fps). You have ammo, you can see the animation but nothing happens. Just Google "rust gun reload" or "rust weapon reload issue" or something similar and you will find a lot of articles. Sometimes it helps if you look at the sky or decrease graphic quality. I've started to play on Geforce Now and I'm 100% happy. No issue anymore and hopefully forever :) 

I agree that it's client performance related. Try to go an area where there aren't bases or people or monuments. When I have this issue, I try to get away from everything then I can reload.