Two guys at bow match had really bad argument about arrow penetration. One was arrow weight and one was speed. To me it depends what you will be hunting. I hunt whitetail deer, I use carbon arrows and have 400 grain total weight. I use magnus stinger 100 grain 4 blade with Matthews bow.
I have yet to have an arrow not completely penetrate a deer. Don't keep count but since I started using carbon arrows, I get complete penetration. I am 67 and shoot 55#. One deer shot, doe quartering away, cut back rib, came out brisker. Not bad for 55#. If I were going to hunt large animals, I might look at heavier arrows, but why for whitetail.
Have shot several hogs broadside, largest only 100# with complete penetration with the 4 blade stingers.

This sort of two different discussions.
What is needed to get a specific penetration potential and how much penetration potential do you need for different animals.

If everything is equal but speed and arrow weight from the same bow, then arrow weight will always be king when it comes to penetration.

A heavier arrow will always give you more momentum and about the same KE than a lighter and faster arrow from the same bow.

The more momentum you have, the more your arrow will penetrate if everything else is equal.
The momentum indicates your penetration potential.

So in theory you can increase the arrow weight more and more(at least up to 2000 grains), and all the time get more penetration potential from the same bow.

But the downside is the trajectory.

So you need to balance it with what trajectory you can accept for the distances you hunt and how much penetration you really need for the animal you hunt.

I think it is totally wrong to talk about minimum KE for different animals and broadheads as many do.
It is much better to use momentum that much better reflects the penetration potential of a setup.

If you have two setups that get the same momentum, but with different arrow weights and speeds to get there, then the heavier arrow will penetrate better.
Momentum generated by weight instead of speed is better as a lighter arrow and faster arrow will slow down quicker and lose momentum faster.


There are lots of other factors that affects the penetration of an arrow too.
Like arrow diameter, arrow surface, arrow spine, tuning of the bow/arrow, broadhead design, broadhead sharpness and more.

gei

I am not an expert on bow hunting.
But before I started I watched a lot of bow hunts on TV. Most of those guys use mechanical, expanding broadheads, and I know their bows are pulling around 70 lbs.
I have yet to see any of them get complete penetration, and many of them seem to have long follow ups.

I used Mangus Buzz Cuts, 100gr with small diameter carbon arrows, for the two deer I have shot. Both were complete penetration, and on the 8 point buck I shot, the arrow went through the shoulder blade on the off side.

My bow is @65 lbs.

At this point in my bow hunting experience I prefer a cut on contact broadhead.

Gei, If you're talking about the typical US Whitetail, from 100 to 225 lbs, you're fine. I shoot 70 lbs and carbon arrows, but use expanding mechanical heads. I've probably shot 50-60 Whitetails with them, and the only time I didn't have a complete pass-through was in shooting a deer straight down between the shoulder blades from a tree stand. Even then, the arrow was only holding on by the fletching. If I were to hunt Elk, Moose, or large Hogs, I'd switch to a cut-on-impact broadhead, which offers less resistance to penetration. Your set-up is fine for what you're doing.

from what I have read and experienced, what noewegianwoods said is spot on.

I am hunting Cape Buffalo in six weeks and the PH recommended an arrow/broadhead combination that weighs 980 grains.

Skin our a Cape Buffalo and you'll see why! Have a great hunt...a Buff with a bow would be a great trophy.

what N'woods says is spot on. for an in depth read, check out dr. ashby's report you can find here
http://www.alaskabowhunting.co...Penetration-W19.aspx

When discussing penetration, with no specific range needed, (i.e., whitetail chest vs cape buffalo chest/bones) weight always, always wins, everything else being equal.

when building an arrow to match your specific hunting style and quarry, you do not necessarily have to go for the highest penetrating setup. as per your example with whitetails, there is no need to go with a cape buffalo arrow for a whitetail, as your trajectory will suffer and range estimation must be absolutely spot on.

the argument will never cease, until we are all in possession of a good physics education

From Cooperjd----(the argument will never cease, until we are all in possession of a good physics education)
Yep, I'm in my 60's and was into bowhunting when all this was evolving back in the 80's, 90's and the early 00's. Lots of discussion like this back then. But it's good, everybody should know the physics of it.
Norwegianwoods describes it pretty good.

I wouldn't hunt buff with the rig I hunt deer with.

Wonder if the Indians worried about this stuff while they were hanging off the side of there horse, shooten there bows, in the middle of a buffalo herd?-- lol.
In a way I'm sure they did,

quote:

Originally posted by joess:

Wonder if the Indians worried about this stuff while they were hanging off the side of there horse, shooten there bows, in the middle of a buffalo herd?-- lol.
In a way I'm sure they did,

I am sure they worried about this and discussed it a lot when they sat around the fire in the evening while eating their last kill.

I have bow hunted for years, started with what today would be low speed, heavy arrow broadhead combinations,, went through the light arrow overdraw speed generation, now i like a balance. You also have to consider the range you intend to shoot at,,,My kill zone is usually inside 30 yards, just like bullets,, heavy bullets drop faster than light ones but light bullets don't have the kinetic energy so like someone already said, simple physics. I now shoot a Matthews heli 70#, 30 inch draw, 350 carbon express with a 125 gn broad head, cut on impact type, steelforce, stingers, montac, slick trick etc,, but not an expandable if I am hunting large animals,, the expandables are ok on light skinned game like deer or small antelope but forget it shooting at a 1900 lb Eland. I have two large eland with complete pass throws with the cut on impact steelforce. The expandables are great on small light skinned animals because of the large cutting diameter but you hit an offside shoulder you will get to test your tracking skills. You get a pass through with an expandable like a rage on a deer,,, holy cow, a blind person could track it. An exit wound sure makes tracking easier when the animal is leaking out of both sides. My hunting buddy that I will be back in Africa again this summer has several large buffalo with his bow, the cape he shot a 90 lb pull bow with a double shafted arrow that weighed a great deal and a 2 bladed broadhead. Weight and energy and sharp stick equaled penetration. It looked like he was shooting a spear! Many Ph's in Africa don't like the expandables due to the rep about poor penetration. I watch too much Tv and see all the bow hunters shoot a deer and they run off with the arrow sticking out of them. I haven't had that happen in many years. I did stick a large Kudu bull that ran off with an arrow once,,,, the shooter was the problem,, bad shot placement.Shoulder joint,, long, long follow up,, not good!.. bottom line is whatever you shoot, put it in the boiler maker and you got a dead animal.

I'm an old timer, been bowhunting 40+ years and still shoot aluminum shafts with Bear Razorheads, on wtd and feral hogs, and an occasional exotic such as axis, sika, or blackbuck. My bows draw 62 lbs (primary) and 58 lbs (backup) at 28" dl. Total weight of my shaft/broadhead combo is 525 gr. One thing often overlooked in the debate is the quietness one gets shooting a heavier arrow compared to the lighter ones.

Personally I shoot a setup that shoots a 615 grain arrow at 260 fps.
Flat enough in my opinion.
It has little sound at the shot and the penetration is outstanding.

I shoot a Matthews Switchback set at 70 lbs. My Arrow weighs 386 grains with a Steel Force, cut on contact broadhead, at 302 fps. I have yet to keep an arrow in an animal with this setup. Even a Bull elk at 60 yards couldn't keep the arrow inside. I agree that heavy equals energy but speed/lighter arrows (within reason) will perform to my satisfaction every time. I usually take a bear every year with my bow, up to a 400 pounder and they don't ever retain the arrow. I tried, for one season, an expandable broadhead and wasn't pleased with the performance so went back to my Steel Force.
Just my .02

quote:

I have yet to see any of them get complete penetration

NE that IS interesting. I too have seen some of these shows where the arrow is still sticking out of the deer. Anyone know why? Choice of broadhead perhaps? I have not shot a deer with my compound bow, but I too thought that complete penetration has been the norm for quite a while now.
Peter.

I wonder if the issue of (lack of) arrow penetration might not be related to the prevalence of 100 grain broadheads nowadays, as opposed to the old 120 grain broadheads back in the day...
Peter.

quote:

Originally posted by Peter:

quote:

I have yet to see any of them get complete penetration

NE that IS interesting. I too have seen some of these shows where the arrow is still sticking out of the deer. Anyone know why? Choice of broadhead perhaps? I have not shot a deer with my compound bow, but I too thought that complete penetration has been the norm for quite a while now.
Peter.

There are multiple reasons for why this is common on hunting shows.
First of all are most/all paid to shoot some big cutting mechanical broadheads.

Secondly are they very often shooting bows with low draw weights to manage to hold the draw for a very long time because of the filming.

And lastly are they most of the time using very light arrows to get as much speed as possible from their low draw weight bows.

This is a great receipt to get poor penetration.

Made first hunt this year, saw many deer, but was waiting for a buck. He never showed up. I was astonished, my friend shot a 180# buck through both shoulders with the new rage 1 3/8 " cut, shooting the small diameter Easton shaft that is heavy for its size. I never dreamed it would penetrate both shoulders. He only shots 58#

I have bowhunted for 40 + years and have taken many Elk, Deer, ,Few bear, a moose, few turkey and a few antelope,few hogs.I started when compound were slightly more faster than a recurve .We shoot heavy slow arrow 2219 was the arrow size with 145 gr bear broad heads slow but efficant momentum is your friend.As time went on the bows became very fast with ultra light Aluminum arrows (still over 425 gr with a over draw)Made a flatter shooting bow my kill ratio went way up.When the carbon arrow came to bowhunting.Bowhunting changed 300 fps speed was achevable and expandable broadheads and gimmicks galore !.But a problems with to light of a arrows were happening.I think now with bows that average 330 FPS rating more hunters are going to mid weight arrow 425-500gr and good quality all steel broadheads getting pass thrus are the norm .You got people being paid to shoot over the top mech broadheads on TV is a problem.But the bowhunters that don't shoot to light of a arrow or way to heavy arrow and use a all steel broadhead will have the most success.

The BH you are shooting (Magnus Stingers)are one of the best penetrating BH's you can buy. I'm shooting the same BH's thru a Hoyt Carbon Element at 62# with Black Eagle Rampage (small dia carbon) arrows at a total weight of right at 400 gr. I've gotten full pass thru shots on whitetail and am using the same combo for elk in Sept 2015. My speed thru my chrono is 286 fps. It works.

Gary

Garby very sound setup.Im shooting a bowtech RPM 360 410 gr arrow at 300 fps at 62# with a Anarchy single bevel it just shoots thru every thing big cali hog quarting slightly away blow right thru the far shoulder arrow was laying on the groud 10 feet past the hog we weigh the hog 314#it was 32 yards.

As a traditionalist with wooden arrows, if it stays in it'll do lot more damage then complete penetration.
Way back when cro magnons hunted to survive, that's how it was done with some superb tracking
That's how I try
Heavy arrows and as close as possible
You people with garage openers, get some guts and go native, then you'll find out how much more fun bow hunting can be besides 10 times the work :-)

Can't be explained any better than how Norwegian explained it. As with boarkiller I'm a hidebound traditionalist. Due to arthritic shoulders 50 lbs. is my maximum draw weight with my favorite being an old Hoyt Pro Hunter from the early 70's at 47 lbs. Port Orford cedar arrows, 5 1/2 in. high backed fletch with Zwickey Black Diamond, 125 gr. broadheads weighing around 525 grs. have worked since then and I've yet to see a compelling reason to change. I'll take penetration every time over velocity, bow, handgun or rifle....with the caveat that has so adroitly been pointed out, you don't need a Cape Buffalo set up to kill a whitetail or boar.

How much penetration is enough?
How heavy is enough?
Which broadhead promotes penetration?

these are age old questions which can only be answered in theory, usually.

I killed a big old trophy bull moose this year with my deer setup and would have had complete penetration had it not been for the off-shoulder blade. The fixed broadhead almost made it through the critter anyway. Total arrow weight 383 grains!

My thoughts are that unless you're hunting big bears or or other dangerous animals, a well tunes deer rig is just fine for about everything.

I'm still learning however, even after 45 years of archery hunting big game in NA and SA.

Zeke

enough penetration is enough to kill the animal quickly right?
you're right zeke, tons of animals, big and small, are killed with light arrows and big cut mechanicals, even though they are a recipe for the least amount of penetration on game.

but i think the heavy arrow guys point is proven with your statement on your moose. "would have had complete penetration had it not been for the off-side shoulder blade"...
what if you had hit the front side shoulder blade going in? would you have killed the moose? sure, the body of the moose slowed your arrow down before it hit the offside shoulder. so there's no real way to tell.

there has been a lot of testing on animals and fresh animal carcasses enough to know that when dealing with big animals, a heavy, high FOC arrow tipped with a long, skinny 2 blade head equals the best penetration (see Ashby's work). but to your point, how much of that is "needed" for most people.

i see it this way. build the heaviest, highest FOC arrow you can, to achieve the lowest speed you will personally accept, so that you are still comfortable with your arrow's trajectory. for most deer hunters that shoot 20-30 yards, that can be pretty slow. for antelope and mule deer hunters, they might need a pretty flat shooting arrow. so it all depends. why not build an arrow that prepares for the worst, and hope for the best when shooting a live, jumpy critter. you hope to slip between ribs behind the shoulder and slice up heart/lungs. but sometimes...there are shoulders in the way.

also folks need to learn how to tune. a well tuned arrow will out perform a non tuned arrow every day, all else being equal. we owe it to the game we're shooting to have our equipment tuned to the best of our ability.

Point well taken Mr cooperjd.

I will gladly shoot a deer or pronghorn through the shoulder blades, on entry, with my rig but I would NEVER attempt a quartering-on shot at a moose or elk with ANY rig (especially with my light arrow selection). I've been at this game too long to beg for lousy results.

I think penetration IS the key to killing quickly but everything can be traced back to hitting the critter correctly.

I don't have all the answers, especially answers for other archers. That's why I posed my questions.

Great discussion!

Zeke