Hello all!
I am kind of new to the forum and have been reading through some old posts. I felt compelled to put my 2 pennies in on this one, even though it's pretty old.
First off, there is no such thing as a "brush gun" or a "woods gun" ballistically speaking. Every bullet deflects and has it's flight path altered when it strikes something. Even the tiniest twig can alter the path of the heaviest bullet or cause it to tumble, unless maybe you're hunting with a howitzer.
That being said, a .243 is just as proficient in the woods as a .30-06. Actually, the .243 may even hold the very slightest advantage because the diameter of the bullet is smaller, and may be able to squeeze past a branch that may catch the larger 30 caliber's jacket.
It's all a crapshoot when hunting in the brush, and most times, it's luck and skill that gets the bullet to it's intended target, not brute strength.
Now, if you're considering a woods or brush gun as just a gun that's easier to maneuver in tight situations and one with the ability for quick follow-up shots, that's a whole 'nother can of worms. In that situation, I 'd always lean towards some of the lever-action rifles and available calibers. I have an old Revelation .30-30 with a 4 power scope that has served me well over the years. This particular rifle is above average in accuracy, and I've taken at least two deer that were closer to 200 yards without the need of a follow up shot. It also is light enough and easy to sling for stalking, and the low power scope works well enough for "up close and personal" hunting in the woods. Some may (and do) prefer open sights for deep or brushy woods.
The next thing that irks me is the belief that a larger or more powerful caliber is going to prevent a deer from running after a well-placed shot. Sure, I think there may be a very slight advantage with heavier bullets, but I've taken alot of deer with alot of calibers, and I can tell you that's another crap-shoot.
I've dropped deer dead in their tracks with a .243 at 100yds or more and I've had them run more than 100 yards after a 50 caliber slug from a muzzle-loader took out their heart at 50 yards. Same story with .30-06, .270, .308, .25-06, .30-30, etc.
I've found that the best deer gun (and we are talking deer here, not multipurpose) is the one that you are comfortable with. I'm sure after hunting with a shotgun and slugs for years you're used to getting your shoulder beat to pieces, so a larger caliber or more powerful rifle like a .30-06 or 7 mag won't bother you much at all. If you'd like a break from the beatings, and still want something you can feel comfortable with out to 200 yards or so, then a .243, .308, 7mm-08, etc would suit you just fine.
So, now I'm just curious, which did you choose, and did they change the legislation?