Welcome to BGH!

I'm not so sure a brush gun is so much about caliber as it is about handling. The shorter lever actions will certainly handle great. Of the cartridge's you choose, do you handload? I don't buy factory ammo but I hear it's also hard to come by now. Seems like the only ones without ammo problems are handloaders and they have component problems. The .444, 45-70 and 308/338Marlin Express might be hard to come by. But if I were to choose one I think I'd get the 338 Marlin. Or if you coul;d find one the 358 Win. I think that both are made on the 308 Win case and if you decided to handload,assuming you don't now, cases are easy to come by. Both those cartridges use very good bullets also.

I have a marlin in the 444p it is obviously a 444. This rifle is very short and is perfect as a saddle gun.

450 Marlin.

My vote is the 450 Marlin or 45-70 with 350 or 405 bullets loaded to 1800 to 2000 fps.

From what i read that 338 & 308 marlin sound pretty good, just a little long for the brush. On the other hand the the 45-70 & 450 marlins are perfic until you get to a clear cut.

We were shooting a friends 450 last Sunday out to 260 yards at a medium sized rock. About the size of a tire. We had no problem hitting it after a few shots. All shots were within a few inches of the rock.

Look into a Springfield armory Socom in 308. I think it has the shortest barrel you can get away with and still be legal, making it a good brush gun....