I had to finally look it up, what's "ROOK" rifle?

I knew it was a smaller and elegant rifle, usually a single shot. Sort of a precursor to the .22 LR farm gun.

"As indicated by its name, the rook rifle's intended quarry was small game including rooks and rabbits.

The rook tends to live in colonies known as rookeries, which over time grow and become nuisances in country areas. In rural Britain it was previously the practice to hold rook shoots where the juvenile birds, known as branchers, were shot before they were able to fly. These events, traditionally held on 12th May, were both very social and a source of food (the rook becomes inedible once mature) as the rook and rabbit pie was considered a great delicacy.

Whilst usually limited to smaller game, the larger calibre cartridges are very capable for hunting larger game such as roe deer, smaller antelope and similar sized game."

I guess my little .310 Martini, rechambered for a heeled .32-20 with .323 bullet, is as close to what I have for a Rook gun.