What would you use?

[runfiverun]

from the list above I'd use anything from the 357 mag on up.
since your buying cast you might as well buy copper wrapped stuff [so the lead is softer]
I'd go with something like the hornady XTP and push it along with some H-110 either the 158 or the 180gr bullet will do the job just fine.
I normally use either the 45 colt, 357, or the 44-40 [carbines] when pushing the thick brush and shots are gonna be close and fast.
i'll take the 44 mag, 30-30, or 45 colt [rifles] if I may have to reach out a bit further, once I get past the 125-150yd mark [ more open ground] I take a normal rifle, or switch to the 45-70 and set the sights so I can click up to 300 yds.