Big objective lenses (possibly more of an eighties thing) to let more light in. Affordable night vision for hunters and the nuances of depth of field for target shooters have replaced the big lenses.

.22 was the same calibre as the most popular firearms so it had to be better. .177 was for effete Continentals. Bigger was usually considered better in the seventies (industries, engines, movies, LPs were doubles or even triples, hair, hems of your jeans and…other things).

Everyone knew of someones brother who had a superpowered airgun that could shoot through both sides of a metal dustbin. Truth be told it was most likely doing about ten foot pounds.