Copy that LUA script that purple posted above and place it in your silent directory (like 'weapons.lua' or something). You'll need to update the script to factor in the silent-specific weapons (the second list he put), but basically you need an array with 51 items, either true or nil. I think all should be "true" except the first one (WP_NONE). What this script does is just constantly set ammo to 9999 for any weapon or weapon modifications (e.g. scoped) that they currently have. Then add this to your config:
set lua_modules "weapons.lua"
Restart your server and test.