Normaly when I hear the term "Brush Gun" I think Short barrel leveraction.
1)They are VERY fast with a bit of practice.
2) Nothing to catch on thick "Brush".
3)Extremely easy to maneuver.
4)Accuracy,practice,find the ammoe that you and the rifle do best with and head shots on what ever are yours at 200yrds all day long.
I have a Marlin Guide Gun stainless .45-70 18.5" Barrel,Marlin 1894ss-ltd .357 with fiberoptic sights,Puma 92 ltd ss 16" .454 with fiberoptic sights.My 1894 is Stainless Laminate stocked and has a custom rail mount with an EOTECH such that the irons can still be used.I will be putting Ghostrings on the GG with tritium front by Brockman's Gen III and custom rear tritium.Goal here is sleak,easy to use sights,hard hitting fast follow up shots...easy maintenance and not afraid to get it messy.
Crawling thru' thickets might give another nod to the levers as you have the whole "same ammoe" thing going on for rifle and pistol.
Give a look at Springfield's M1 SOCCUM....nice sleak profile,16" barrel,great sights that have tritium for low,or no light...reliable and fast follow up shots.Fast reload box magazines and plenty accurate out to 500m and .308win is good for anyhting in the lower 48.
It is a bit on the heavier side of things for brush carry I guess.
Wanta B