I've seen a few methods for creating zero stops for non-ZS S3 scopes, usually using a plastic ring around the outside of the turret. After a little measuring, I was able to find 1.062" OD washers from McMaster that fit closely inside the turret. They're fairly thin, and allow for reasonable adjustability. Just pop them in and go.
Adjustments per shim:
Al 0.016" ~ 2.7 MRAD
Nylon 0.031" ~ 4.5 MRAD
To set the zero ~2 MRAD below optical zero, I needed 0.314" of total shim. So that's a decent starting point.
Edit: either washer pack comes with enough to reach more than 0.314" total stack height. So if you don't mind a little rattling from just the Al ones, a single pack is sufficient.
Adjustments per shim:
Al 0.016" ~ 2.7 MRAD
Nylon 0.031" ~ 4.5 MRAD
To set the zero ~2 MRAD below optical zero, I needed 0.314" of total shim. So that's a decent starting point.
Edit: either washer pack comes with enough to reach more than 0.314" total stack height. So if you don't mind a little rattling from just the Al ones, a single pack is sufficient.