1) the bullet rises as it goes downrange
Without doubt one of the most common misconceptions I run into right there.
If you do not indoctrinate some kind of elaborate barrel break-in proceedure... your rifle barrel will be ruined and it will never shoot better than 2" at 100 yards!-
This one is still going strong as well. I have read several good articles by people who know far more about making rifle barrels and putting together accurate rifles than we ever will that just blasted these barrel break in procedures as utter laughable nonsense.
That the term "Brush Gun" means a gun which fires a heavy bullet that isn't easily deflected by brush. When the term was of course originally coined to describe a shorter version of a gun that was easier to carry, maneuver and aim in thick brush or cover.
I also find it funny when I see people blown backwards, often through windows or doors,in movies by gun blasts. Bullets don't push you anywhere. They just strip through your @$$.
I carry a magnum rifle because it gives me a little more margin for error. In what way? A miss is a miss whether it's with a 243 or a 300 win mag. And a poorly hit animal has a good chance of not being recovered regardless of what you shot him with. Larger caliber or cartridge sizes do not lessenthe need for good marksmanship.