Advantage of 85 vs 100 grain broadheads?

[Ray]

Kinetic energy is a useful measure because it's all over the place and easy to determine but it does not always translate into greater tissue penetration capabilities. See reports in link at the bottom where some higher measures of KE were not translated into better penetration than lower KE tests.. One Point - Some broadheads will work better than others. 2 blade tend to penetrate with less resistance and will likely drive into flesh or bone farther than the 3 or 4 blade. The only advantage of the 3 or 4 blade is the so called "wound channel". Which can be achieved with a 2 blade single bevel and which to people like me is not really an advantage when you loose depth of penetration for a wound channel which might only be on a non-lethal part of the animal.

I don't pay a lot of attention to kinetic energy at all and I don't think it is what I should be concerned with as much as another measure of penetration which is termed "tissue penetration index" and another measure termed "slug feet per second" as well as "mechanical advantage" and even more imprtant than KE to me is "Momentum". Which are actual measurements or ratings that are applicable to the whole composition of the arrow and that can be translated into success a lot better than the simplistic kinetic energy. Kinetic energy does not necessarily equate to better penetration as quite often than not suggested to people. All things being equal it might be some measure worth looking into but often times people are not measuring exact same setups.

More notes for those who want to find out the science behind the terms

Full Reports and Science

[fishwhackin]

Depends on how heavy your arrow is, cutting diameter of the broadhead, what you are hunting and how good of a shot you are.  Light broadheads are great as long as you have a bow that puts out enough speed or energy to get the light arrow/broadhead into or through what you are wanting to take down.  If you are a good shot, shoot low poundage and shoot super light arrows.  If you know that you have a good chance of missing left or right on a regular basis then you better cover your @ss and shoot heavier arrow/broadhead combinations with a strong broadhead that will bust through that shoulder blade and or bones.  Important part of my advice is that if you are practicing and know that you can put your arrow in the vitals better than 90 percent of the time, the good and bad of each option just about even the two choices out under different circumstances.

[D-Rock425]

the difference in kinetic energy between 85 gr. and 100 gr. at 315 fps is 4 more foot pounds with the 100 gr. broad head. and kinetic energy is what we all should be concerned about.  lets face it not every shot will end up in the perfect spot, after all we are human

I think most of us on here cant shoot a hunt legal arrow at 315 fps.  so for most hunters it will be less then 4 foot pounds of kinetic energy.  If you geta quility 85 grain broadhead on a hunt legal arrow I thing it will do just fine.

[stickslinger]

sorry for that I just took my set up and took 17 fps off and figured that was a good number to throw out there. and yes that was with a 365 grain arrow. My point was that if you can get more energy out of an arrow that can equal better penetration with out loosing that much speed than why wouldn't you go with the heavier broadhead.

[carpsniperg2]

a few more fps with the 85 and a few more foot pounds of ke with the 100 usally the cutting diffrence between the 2 is like 1/16" bigger on the 100grain, so not to much diffrence between the 2 

[Intruder]

Kinetic energy is a useful measure because it's all over the place and easy to determine but it does not always translate into greater tissue penetration capabilities. See reports in link at the bottom where some higher measures of KE were not translated into better penetration than lower KE tests.. One Point - Some broadheads will work better than others. 2 blade tend to penetrate with less resistance and will likely drive into flesh or bone farther than the 3 or 4 blade. The only advantage of the 3 or 4 blade is the so called "wound channel". Which can be achieved with a 2 blade single bevel and which to people like me is not really an advantage when you loose depth of penetration for a wound channel which might only be on a non-lethal part of the animal.

I don't pay a lot of attention to kinetic energy at all and I don't think it is what I should be concerned with as much as another measure of penetration which is termed "tissue penetration index" and another measure termed "slug feet per second" as well as "mechanical advantage" and even more imprtant than KE to me is "Momentum". Which are actual measurements or ratings that are applicable to the whole composition of the arrow and that can be translated into success a lot better than the simplistic kinetic energy. Kinetic energy does not necessarily equate to better penetration as quite often than not suggested to people. All things being equal it might be some measure worth looking into but often times people are not measuring exact same setups.

More notes for those who want to find out the science behind the terms

Full Reports and Science

Well said.... couldn't agree more.  Much of that translates to firearms too.