Love that matched pair! Thanks for the reminder, Clay. I had watched the start of that clip before, but didn't get that far before being dragged away...

No doubt the existence of the .22 Rimfire, and rifles so-chambered, was the ultimate reason for the smooth-boring, but I believe the catalyst for forcing such action on obsolete rook rifles, probably held as curios for decades, was the restrictive 1968 UK Firearms Act.

From our point of view today, it is certainly a tragedy.
...as is often the case for firearms legislation "reforms" perpetrated by overbearing police forces or self-serving politicians.