I am a plinker and not now, nor have I ever been a hunter.....
....But when I went with my uncle, back in the day, he liked his 30-30 a 336 Marlin as a brush rifle because it was short and light, he chose a rather heavy slug, he did not need to reach out very far where he hunted in southeastern PA so no scope was needed. The MV was somewhat low so the the trajectory was not disturbed by twigs and such. These are the qualities that, for him, defined the brush rifle. He also had a place in Lycoming County where the shots were far longer. For that he liked a 270 (Remington 700). Still heavy enough to provide a straight shot in undergrowth, but more umph to reach out a little further. On that rifle he used a four power scope. He sighted it for 25 yards and it was spot on at 200.
Isn't it true that the term, "Brush gun" has a pretty wide range of descriptions?
A brush gun in SE PA is different from a brush gun just 200 miles away.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson