Viper PST 6-24x50 with Leupold Alumina objective cap


Well-Known Member
Jan 25, 2011
Bozeman, MT
In case anyone else is interested and finds this thread:

I did email Vortex about this and they let me know that they do not believe the Alumina caps will work on the Vortex optic.

Apr 15, 2015
The threads on a Vortex Viper are 52mm. The objective lenses on numerous scopes are 50mm, however their housings are not always uniform in size or diameter.

If you go to B&H Photo or any other camera site/store, you can buy step up or step down adapters that allow photographers to use different filters on larger or smaller diameter lenses. These also work for scopes.

I mounted a Leupold Alumina 50mm cap on my Viper PST using a 52mm to 55mm adapter. Threading the Alumina cap onto the 55mm end will be a little bit snug, but it works.

As a sidenote, using camera filters on your objective lens (52mm filters for the Viper PST) will give you a sacrificial lens and a variety of filtering options for increasing intensity, plain UV filtering, etc. Higher end filters will prevent any distortion or issues with clarity or light transmission.

Hope that helps.