Speed v's Weight

[Skipper]

Speed v's Weight

A bunch of us were crowded around the counter at the archery shop yesterday evening and one of the guys was bragging that his bow was shooting over 335 ft/s. I realize my bow isn't the fastest on the market, but still, it's pretty dog gone fast. In hunting trim, I shoot about 275. That's with about a 450 grain arrow. Turns out, speed deamon is shooting a carbon arrow and 80 grain broadhead that totals out right at 200 grains.

IMO, speed is nice, but penetration is better in the woods. I've never failed to get a pass through even with my older bow that was just a few ticks slower than my current rig. I'd think if he was using a similar weight arrow, he'd find himself shooting a similar speed.

The difference in energy is about 72 footpounds on my heavier slower rig v's about 44 footpounds on the faster lighter set up. Which one is going to get better penetration? Obviously the heavier slower rig.

Question: There has to be a happy medium somewhere. Should one take the needed energy and work backwards to optimize arrow weight and speed or should you simply try to get the fastest arrow you can get? I know what the advantage is to having a fast arrow, it's using fewer pins on the sights, but where do you cross the line by getting too fast but not having enough punch at the end. Kinda like hunting with a 22 rifle, it's fast, but ain't gonna do the job.

Skipper

[Rmouleart]

I use a 2215 eastons with a 125gr Thunderheads broadhead, traveling around 320 fps, using a over draw, twentyeight inch arrow, using a free flight release, this bow is set at 85 pounds, good thing I lift weights, not that much letoff like the newer bows. This is Pierson spoiler, I bought this bow back ten years ago to not only hunt deer but big game like moose/bear/elk big bodied game, this is where your speed and heavy constructed arrows will play in, I like heavy constructed aluminum arrows for big game, never cared for carbon, shatter too easy when hitting a solid bone. The heavy 125gr thunderhead broadhead makes the arrow even have more driving power for deep penetration and a good chance for a pass through on big game if the shot is properly placed. Aim small hit small. RAMbo.

[Dalton]

Skipper,

I don't think there are any proven ways of calculating penetration, which seems to be what you’re really asking.  There are too many variables, flesh density, bone density, broadhead type, arrow diameter....  

I have seen charts where you can calculate your arrows kinetic energy by providing speed and arrow weight.  That number in my opinion means nothing, because arrows don't rely on kinetic energy to do their work.  Arrows kill via hemorrhaging the animal.  It has been my experience that a hole on two sides of an animal by a broadhead with at least three blades is the best way to do that.  

Without any firm mathematical way of calculating penetration I use a method told to me when I was a kid.  Take the draw weight you are going to be using while hunting and add a 0 to the end of it.  That number is your arrow weight in grains.  I am shooting a 60lb. bow and my arrows weigh 600 grains.

This method has always worked for me. :grin:
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[flintlock]

I think its all personal preference and hunting style...kinda like buying a muzzleloader and expecting to kill deer at 200 yards...When I muzzleload hunt I don't setup for 200 yard shots....same with a bow...
I started with a 45lb Bear recurve and Bear broadheads in the early 70's...
my brother and I killed several deer with that bow...all were within 20 yards...About 1975 I bought a Bear Whitetail...set at 55lbs, shot 2114 arrows I believe...31 inch draw, with Satellite 3 blade broadheads...shot alot of deer with that setup...used 4 pins...shooting fingers...no peep...
Currently I use a Mountaineer Bow (no longer made) set at 60 lbs, Whisker Biscuit rest, 2 pins, fingers, no peep and 31 inch 2413 arrows with either 125 Thunderheads or 125 NAP expandables...Top pin is set at 20 yards...I'm only about 2 inches high at 15 and 2 inches low at 25...lower pin is set at 30 yds....I've never shot at a deer at over 25yds...
In NC, during bow season the woods is still thick, 20 yards with no shooting lanes is a long shot...so I just setup for closer ranges...If I hunted were I might have longer shots, I would probably have a different setup....But, my bow tunes easily, shoots quietly and I get full penetration when I kill a deer....I guess I feel like if you bow hunt, the thrill is to get the deer within 20-25 yards...If you hunt with a muzzleloader, get the deer within 100-125 yards...Its all about what you prefer, and not expecting technology to help you fill your tag...Some of my buddies have tried to talk me into shooting a release...I like the string between my fingers...I'm used to this...Within my ranges, it works for me...same as muzzleloader hunting...I do own a Knight...killed one deer with...went back to my .54 flintlock...I just prefer, and it will do the job...
When I get serious about thinning some does on the farms.....I use my Ruger .243.... :-D  :-D  :-D Fortunately in NC...we have a 3 1/2 month season.....Good Luck....flintlock

[Daveinthebush]

I agree that there are too many variables.

I shot 2 bears this spring.
Bear 1 = Pearson Flame, 75 pounds, 28" 2213, 125 Thunderhead, 550 grains, (I believe 220 fps) - 20 yard shot, bear squared 7'2"
Bear 2 = BowTech Pro Wheely, 62 pounds, 29" Easton Axis 340, 125 Thunderhead, 450 grains, (factory rated at 321 at 70 lbs.) - 10 yard shot, bear squared 5'4".

Bear one died within 40 yards a complete pass through. Bear 2 died within 20 yards a complete pass through. Both double lunged.

I have seen a lot of archery shows on the Outdoor Channel where women are shooting bears with a lot less and doing just fine.

Placement of the arrow is everything!

[Skipper]

My bow is pretty flat shooting as is.  Out to about 30 yards, I can and do use 1 pin.  I'll hold a little high over 25 yards, but not much.

In the woods around here, over 25 yards is pretty unrealistic of a shot, and I can't immagine over 30.  The only place you'd get any farther is shooting over a pasture or crop field, and there are few places for that here.  I'm perfectly satisfied with my rig's performance, and really not excited about trading except for a couple of things.  1, my bow is 6 years old now, and you know how it is, you go look at the new creations and lust a little, but then I look at the price sticker, and that kinda puts a hold on the lusting for a little bit.

I tried carbon arrows once and absolutely hated them.  I busted 2 of them.  One evidently cracked on the previous shot and I didn't notice it.  The next set when I shot it, splinters went everywhere.  My thought then was, i don't want that in my meat.  What if it blows up in the deer?  I'd have to discard a lot of meat to insure I didn't get a fiberglass splinter in my neck.  Those were early versions, and I'm sure they have improved.  Still, I went back to shooting my aluminum Eastons and never looked back.

I would think if I were shooting under 220 fps and had to have 3 pins to do it, then there might be a gain to be made by speeding up.  At 220 with a 540 grain arrow, you are at 58 foot pounds where I'm at 75 with my set up and a 450 grain arrow.  His 46 or so pounds is significantly less than either, and I wonder if that's sufficient.  I suppose the smaller diameter arrow will still make it though mostly because there's less effort required to push through a skinnier shaft.

I wonder on these new rigs, when they advertise a speed what are they shooting to measure it with?  When I went from my Whitetaill II years ago to my first Hoyt, it was night and day difference in speed, the second Hoyt isn't much faster than the older one, but still has there been some leap in technology that has pushed the speed up again without sacrificing the bullet so to speak?  I saw on one bow site a guy claiming his bow is shooting 400 fps.  I don't believe that for a minute, but maybe it's possible.

Skipper

[Rmouleart]

I use my F1 chrony to measure the speed of my arrows, This works due to a casted shadow of the object over sensors in a box with rabbit ears sticking out to give you reference where you need to pass over your object,this reads the FPS, I of course use the f1 chrony to measure my bullet FPS, when reloading and working a load. Keeps us honest. Aim small hit small. RAMbo.

[cam69conv]

Howdy all

 On my rig Im set up at 70#, 29 1/8" arrows total arrow weight is 332grains including 100 grain head, I get 297fps..Now I just switched to these arrows from 11 grains per inch which all added is 419 total with 100 grain heads..I see about 2.5 inches difference on penetration (black hole target) with the new arrows..Them going deeper...They are the same diameter and both carbons..I noticed on  a previous submission about the strength of carbons...I have one arrow from the year before last that has killed 4. Sorry I used aluminums for years myself and I have yet to get more than 2 kills before its to bent to much to straighten out..Ill refletch it and run it through another one this year..Changed rigs last year so I didnt get to use it..So back to the question...Im actually seeing better penetration with these lighter arrows..Now granted Im not threadin the needle Like your friend at just 200 grains total weight...He will regret that himself soon enough when his bow exploads from too lite an arrow..another question asked was how they get the speeds...All bows that advertize IBO speeds are shot at 70 pounds...30 inch draw with an arrow at 5 grains per inch and no tip or fletches shot through a chrony...so...your average individual should just subtract around 25 feet per second when looking at a new bow. I have fretted much on this particular question myself as last year I was having a little problem passing through. Easton does have some good calculation pages to calculate your kinetic energy..Not sure if Its on its web site or not But I have seen them on several bow mags...

[Skipper]

Here's the KE formula

(arrow weight (in grains) x speed^2 (in ft/second))/450,240

Skipper