Thread dredge...
Had a POSP once, early one with the IR filter even.
Great scopes those POSP descendants, and pretty solidly built, but the range knob is calibrated for 7.62x54R in 50 meter increments. So, unless your round has the same trajectory, you're SOL.
I don't know how long it's going to take these guys to figure out Minutes of Angle, but I hope they do it soon. They build great stuff at great prices, mostly, but why, oh, why can they not build what the market wants? 15 kinds of POSP is not what we need.
Quite a contrast with IOR Bucharesti who started from about the same point and are now way out in front of the pack with technical innovations and quality/price.