Yana,

I use an Anschutz 6702 (Centra Score front tunnel) on my TX200, and Gehmann 590s on my HW30S, HW99S (both HW front tunnel), and HW95 SuperMatch (Centra Score front tunnel).

There is no problem zeroing them at 6 yards, either with aperture inserts, or post.

Have fun & a good weekend

Best regards

Russ