Comparing bows in terms of killing power...for lack of a better way to say it.

[archer66]

I'm still a traditional newbie....I've been hunting with my 66 Bear Kodiak Magnum for two seasons and have a lot to learn.  I'm going to be in the market for a second bow soon and have a question.  Hopefully this question has a real answer...

Lets say I have two bows...same draw weight, same limb length, same string, same arrows, same draw length....will one bow have more downrange energy than another and is there any way to predict which bow will come out on top?  What factors come into play that affect downrange energy....riser design (deflex-reflex), limb design ( stored energy at full draw), overall bow efficiency????

For instance:

52 pounds at 25 inches
Bow length 54 inches

[Stumpkiller]

Yes, but it is going to be hard to qualtify it.  Two AMO 58" bows I own: one is 47# and the other 48#.  The 47# bow throws the same arrow what seems to be 10% faster and harder than the 48# bow.  Should not be so.  Obviously the lighter bow converts potential energy to kinetic energy more efficiently.  Limb design, air drag, string silencers required, brace height for good flight, rest material, finger pinch (less = smoother release), etc., etc.

Also, a smooth initial arrow flight (less paradox/kick/wobble) ALWAYS produces better results for penetration or energy on target; and accuracy as well.  I think the primary reason I have done better with recurves vs. longbows/flatbows is because I have never owned a center-shot longbow.

[Matty]

Great answer

[jsweka]

If both bows are shooting the same arrow, the one that shoots faster close to the archer (i.e. through a chronograph) will also be shooting faster down range and have more kenetic energy and momentum at the point of impact.

In general, a recurve will be faster than a r/d longbow (but some r/d longbows are just as fast as recurves) and a r/d longbow will be faster than a straight limbed longbow.

[archer66]

Are some bow models KNOWN to be harder hitting than others?

I know that keeping shots close with a well placed arrow is of foremost importance in all bowhunting and I know that a razor sharp broadhead on a well tuned arrow that flies straight and true is also a requirement.  However since penetration/pass through on deer sized and larger wild game is also important I want to do what I can to give myself any advantage I can.

[chanumpa]

Very well written answer by Stumpkiller to orig,question.Second question,Id say more poundage,as long as you dont over do it,(overbowing yourself).Of which I have done.Find what fits your bow hand and draws smooth for you.Good technique/practice,and persistance will reward.

[Running Buck]

Tuning your arrows(bareshafts) to obtain the best possible flight will result in the best energy transfer to the target. That being said, the comparison between two bows in relation to energy would be rated in dynamic efficiency. Take a look at some of the bows R. Blacky Schwarz has tested to the date, his findings will show stored energy,stored energy per pound of draw weight,Dynamic efficiency etc.

[ChuckC]

My thoughts. .  although we tend to downplay speed. . .  (you don't  NEED to be supersonic), fact is once the arrow is off the string, the bow no longer suppies anything towards that "kill" goal.  Comparing speed of THE SAME arrow between different bows can be quite telling.

Some things to keep in mind. .  everything else has to be the same, including arrow flight.  If one kicks an arrow 5 fps faster, but it does not display good clean flight, that will negatively affect the situation.

I believe, when it comes right down to it, if you are comparing things that are THAT similar, the difference in "kill power" will be so negligible that you shouldn't waste your time worrying about it.  There are other things that will make more of a difference.

ChuckC

[Jay Campbell JD]

stump killer, excellent answer. There are definite differences in a designs' ability to deliver more energy. but, if you do not have the same degree of perfect arrow flight, let alone arrow design (small shaft, FOC, 2 blade head, etc), you will not be able to take advantage of it. My real world example: a 70# Adcock ACS and a 80# Black Widow PLX. After a great deal of work and tuning, both bows used the same arrow (1020 grains) and delivered it at the same speed (166 fps). So, momentum was identical, despite the 10# difference. My wife shot the Adcock, I shot the BW. Both bows took buffalo with one arrow. Nonetheless, I gladly gave up the energy advantage of the Adcock because of handling, toughness, and my perception of "shoot ability".  Point being: energy isn't always the full answer. :-) - Jay.

[jimboby]

All good answers above.  I often play "what if" games on Stu Millers calculator, especially the latest version.   I can compare bows that I currently own or am thinking of owning.  The end result showing ft/lbs of energy out of a given setup.  For example, I have a 45# r/d longbow that shows 35+ ft/lbs of energy with a given setup(high foc, gpp, etc.).  My 53# recurve shows 41 ft/lbs with a good arrow setup(different than the longbow).  Both bows have killed deer with full passthrough shots but I would use the recurve for an elk sized animal based on this.  If I want to buy a new bow I can plug numbers in the calculator for it and a good matching arrow setup to predict killing power vs what I am shooting now.  This method won't help decide much else about a bow though.

[Roadkill]

Stump, great reply with incite.  Thanks for both the question and the answers

[Bjorn]

About 7 years ago my shoulder needed a break so I moved down in bow weight from high 50's recurves to a 49# ACS CX. I was able to continue using the exact same arrows and shoot them at the same speed. So yeah some designs are better and carbon won't hurt either.