RE: Perfect Deer Rifle
Rick, I too remember the Ruger MX-1 or XM-1 semi's that were to hit the market back in 1985 or so, in .308 first, then in .243. They could never resolve a problem with the barrels heating up to much and actually warping, so they canned the whole project.
In thick brush, and I know a little bit about thick brush, a bolt or single shot is the perfect rifle. In thick brush, or open fields for that matter, your first shot is going to be your very best shot. Any shots after that is just wasted ammo. It is the quality of the shot, not the quanity.