Main File
2K Textures

Higher Resolution 4K Textures.

Fixes Attachments appearing on other weapons
Increased reticle resolution, might look better.

Optional nif files without glass lenses for people experiencing the purple texture with AMD cards.

If some of the sights are fine then remove those nifs from your Data\Meshes\SG550\Attachments\Sights and let the archived meshes load.