Welcome to the site you can get a lot of good information and you'll see alot disagreements. Especially about heads and bows.

Like someone already said it's not all about cutting diameter, many of the pros you'll see promoting a head or a bow this season used totally different equipment one or two years ago.If you have a good shop in your area they can help you out and so can the internet. There are KE calculators available and many tests independent on broadheads available.

One thing to pay no attention to are people that made the perfect shot with broadhead X but never found their deer so it's the heads fault. You make the perfect shot you kill the animal and they aren't hard to find.

Any sharp head that is put in the right spot is going to kill an animal quickly. Sometimes that doesn't happen and that's where the good ones are seperated from the bad. We might not be shooting through metal barrels but shoulder blades and spines are pretty darn tough.

As important as a good broad is knowing when to pursue game after the shot and how to track. More animals ar lost due to not giving enough time on a marginal shot then just about anything.