The sniper scopes that were made for BZ don't work right in TRO. Instead, you should use sniper scopes that work correctly in TRO, which are included in this file:
BZTROSniperScopes.zipIncluded in this file are the 3 custom sniper scopes for BZ that are already available, as well as the 3 same scopes made to work in TRO. It also includes backups of the default sniper scope for both BZ and TRO. (The red dot)
Extract the zip file, then find which scope you want. Copy the files for the desired scope to your addon folder. TRO scopes are for TRO addon, and the BZ scopes are for BZ addon. It will ask you to overwrite some files, so when it does, click "Yes" or "Yes to all".
If you want a custom scope in TRO, it's now possible. Enjoy!
EDIT: Added Red Circle with dot scope from a very old BZ installer.
EDIT 2: Fixed Broken Link