My buddies and I all had nylon 66’s in 1965.
They shot great for our needs. (Rabbits, squirrels, grouse, crows, tin-cans, etc.)
In later years we mostly navigated to 10-22’s, as that was the new fad.
The 10-22’s didn’t shoot any better or worse, for our purposes, but we felt better because we were following the trend.
Loved that old 66....