Looking for a 6x scope with adjustable objective down to 10yd. Must have a mil-dot reticle. Will be mounted on a CO2 airgun so recoil is not a concern.

Nikko Stirling 6x40 Mountmaster would be perfect but I cannot locate one on this side of the pond. RWS made a 6x as well but can't find one of those either.

Any suggestions?