Used to love those scopes & seeing them on single shot varmint rifles of the 50's and 60's.
I used one in the 1990 BC Summer games on a .222 Sako. The spring was missed and the scope moved about 3/8" forward at each shot. The scope had to be pulled back after each shot or the next one would drop out about 1/2" low. Prone match & I got the gold, but only shot a 99 6X. I was quite excited after seeing 9 10's in a row, and forgot to pull the scope back on the last shot. IT happens.