The mod (or animation, to be precise) uses Urik Particle.

What's up with your missing particle

its possible .

oh i though it was a audio mod that made it sound like people were fighting the infected in the city

its just ambient sound on youtube ( ╹▽╹ )

whats with the random talking and gun firing in the background?

I understand what you say , however i don't know what caused this .
But here is something i know :
- While script indeed control how long it take to reload , it's not the only factor that decide it . From what i know the script only speed up or slow down to match with set value
( i.g. 2.2s is 100% scale , if you set it to 1.1 which is 50% scale , anim will play at x2 speed ) .
In other hand , my MW mod also have a built-in fast reload which doesn't speed up "reload" anim ( it isn't script but act like script ; i will talk about that in a guide ) .
- When you host a game ( regardless of offline or online ) for the first time after you boot up L4D2 , game will load all the script and will keep those script until you quit L4D2 . So make sure to reboot L4D2 everytime you make change to your script .

I used your MP5 ADS CS GO version and it works great. Reload animation slow happens 100% all the time with this mod though the exact animation seems to alternate (slight variations in the slowness about 1, 2, 1, 2 pattern), and can confirm it's due to some mod script stuff. When I go to default settings (or my mod order is changed) , animation works right. But my script doesn't change reload stuff other than reload time. I even tried setting it back to default 2.2667 seconds and still doesn't fix it (ignore "file" : "vgui/hud/mp7" , I have a custom mp7 folder that has a Bizon HUD icon, I'm strange I know)

(script) https://pastebin.com/W6UEJU8S

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2929450302
Please try this mod and see if it has same issue .

By the way , how about my MP5 ADS ? Does it have same issue ?

I see . I might have an idea , but what script mod do you use ? ( just curious )
Also may i know in which condition did you experience slow animation , or it happened all the time ?

Hey @Artillery Rain, big fan here (I'm suscribed to multiple ADS mods from your CSGO collection). I have tried this one and the Bizon Cod ADS mod, and both of these mod while working, have desync animation reloads with their reloads. Notably, I have a custom reload time in my weapons script for both silenced SMG and UZI, but I don't have this issue with any other mods, including your own. Just these two COD ADS mods. Any thoughts? Would love to use them both, but animation is very very slow, and the reload is correct speed but the animation just syncs up at the last frame by speeding up instant quickly