If you are referring to what some people call a brush gun, don't be misled into thinking a slower heavier bullet will stay on course if it hits a branch. You just got very lucky with the .270 and a 30 caliber probably would have resulted in the same ending. There have been test done and they have shown that the slower heavier bullet fares worse that the lighter faster bullet does when it hits something between the gun and the intended target. I am sure you have watched a football game where an opposing player tipped a pass and the ball wobbled and did not go to the intended target. Same principle with a bullet.
Forget that fallacy and look for a caliber that you can use for multiple applications and for multiple species. and don't try to shoot through brush.