NOT to change the topic...just replying to a question stealthycat had.
Yes, NORMALLY bigger diameter means LESS penetration. However, SOME tests have shown SOME mech heads CAN cut a bigger hole AND penetrate better than some fixed blades. That is 1 reason SOME MIGHT choose a mech head.
even with FIELD points, and a 350 grain arrow going at 300 Fps, in a 10 mph cross wind, at 30 yards, you will be off by 3.2"!!! 30mph (who'd shoot in that...I know you were kidding, but....)you'd be off by 9.5"!!!
This is WITHOUT broadheads!!! Add a big fixed blade, and you can see the problems you COULD face