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Permanent Shells

How to install this?
So, unfortunately, the modded files are .txt files and won't be automatically installed. Instead you have to follow these steps for the permanent shells to work:

1. Subscribe to this mod.

2. Create a custom folder in the Black Mesa directory by following this guide: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=502670746

3. Go to your Steam folder and look for a path like this: *\Steam\steamapps\workshop\content\362890\3035568956\Permanent Shells.vpk

4. Copy "Permanent Shells.vpk" and paste it in your custom folder.

Put this in your autoexec.cfg for .357 shells to stay permanently too:
cl_weapon_shellbrass_life "4096"

Description
Finally, there it is. I found this to be one of the more significant improvements to the aftermath experience. It is surprisingly not that resource intensive and completely playable in regular gameplay (i.e without cheats). Before this I had a different method which required you to recompile weapon models and edit QC files which was impractical since you couldn't use the addon with custom weapon skins, but then I found about this little thing called weapon scripts which let you modify events. You can combine this mod with the other ones that change bullet shell models. Enjoy.

I highly recommend this mod for bullet shells. I personally found these to be the best, because they are noticeable and fix the wrong collision the default ones have:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2975843662