Did a speed test today
Elk
Contributors to this thread:
Got interested in what my bow really does for speed. Took my new chronograph out today and did some shooting. Right now I can't remember if my bow is cranked all the way or not, did not feel like it so probably only at 65lbs. Anyhow at point blank arrows shot 282 fps which equals 69.98 ft/lbs of kinetic energy. At 20 yards, 275 fps and 66.55 ke. 30 yards = 268 fps and 63.20 ke. 40 yards = 264 fps and 61.33 ke. Ke was using a web site that calculated it. My arrows weigh 396.2 grains. I was sup prized at how little speen was lost at further distances. Did not feel like trying a 50 yard shot over the crony today…a little shaky!!! Not trying to rattle anybody's cage, just thought this was interesting. Now hope I get lucky in the draw for a tag! Arrows shot were Victory VAP Xpert series 350's with a 100 grain field point
That is pretty cool and pretty informative for.
Good luck, Robb
Feathers or vanes (questions mark) - my question mark key isn`t working, I am getting this: É
Vanes. Short ones. My draw length is 29 inches. These are Victory's skinny arrows.
http://peteward.com/ballistic.calc.htm
Enter your data into this calculator, you'll get about the same answer, so your data is pretty good (or the calculator is pretty good depending on how you look at it!), and you don't have to risk your chrono on that 50 yd shot.
Nice work Tom. I want to do this now.
see how fast my 560 grain arrows fly
good info - thanks... Seems like you are set for anything in North America.. (provide of course, you don't mess it up by screwing some controversial broadhead on the end of it and ruin it all) LOL
Jack, don't plan on doing that, LOL. Am going to use slick trix mags.
Another speed test...another light arrow. Why not do a trajectory test that might point you to a heavier arrow that might lead to better penetration that might lead to more recovered game...you know....next level stuff.
Another speed test...another light arrow. Why not do a trajectory test that might point you to a heavier arrow that might lead to better penetration that might lead to more recovered game...you know....next level stuff.
no one stoping you from doing that is there. waiting for your results
Nice work Tom.
396 grains is not a lightweight arrow, as you well know.
Some folks just go around looking for trouble, or trying to start some. In person, some folks could get a "next level" bloody nose.
I hit my cow elk square in the shoulder blade with a 357gr arrow at about the same speed as your setup and still got acomplete pass through. It didn't rocket out the other side but did fall out of it as she made her last 60yd dash. Put it where it counts!
That set up is a little light for turkeys, but you're good to go on anything else in North America. :)
Nice test. Personally I love an arrow weight right around 400. Fast flying elk killing machines.
i shoot a fmj at 525 gr arrow at 260 fps. giving me 78.84 ke and momentum of .604. momentum is more important than ke.
not trying to poke a hornets nest, trying to learn..why is momentum more important to you?
ke is more of gun thing. a arrow going through only cuts tge contact area. unlike a bullet going through with high ke explodes inside. therefore a higher momentum will push through a shoulder. but you can get a higher ke woth a fast light set up but the momentum drops and the momentum is what you need to push through. ke is more of a gun thing doesnt impact as much with archery.
Definantly not enough for a huge mechanical and turkeys...I shot a 440 grain with 72ke and nearly bounced off big Nebraska toms. I went to 535 gr and got a noticeable amount better penetration and no difference in trajectory at 25 and under.
did a lot of reading and did some research on momentum and found this, Note: the best arrow/broadhead combination tested provided a momentum of .57 lbs-sec.
TO ACHIEVE .57 POUND SECONDS OF MOMENTUM: (The momentum of the "Best" performing arrow/broadhead combinations in study, all of which had broadheads of 3.0 mechanical advantage):
A 740 Grain Arrow must reach a velocity of 161 Ft./Sec.
A 550 Grain Arrow must reach a velocity of 234 Ft./Sec.
A 450 Grain Arrow must reach a velocity of 285 Ft./Sec.
A 350 Grain Arrow must reach a velocity of 367 Ft./Sec.
I am still learning and may try a little heavier arrow just to satisfy my self and see how much arrow drop there is at longer distances.
How come when I shoot against my buddy who shoots 50g more than I do with the same draw weight that my arrow penetrates further than his?
When we back up past 50 yards which I would never do on a live animal his arrow then penetrates further than mine?
Why the difference only after we back up and why is mine doing better from 40 yards and in?
My arrow travels at 300FPS and is an ultra light. His arrow is traveling at 280FPS and is 50G heavier.
i really dont see importance of speed. louder bow, not as much pentration. and me shooting a 525fmj at 260fps i get .604 momentum. enough to hunt anything but elephants. who cares about speed i want a pass through where ever i hit.and i used to shoot 310 fps with a lighter arrow. and really not much difference in pin spread shooting 260fps. ill take a quite, heavy, more pentration arrow any day over these guys complaning about 320fps vs 330fps. at .604 momentum my arrow has way more pentration anyways
Well for me speed means a flatter shooting bow. I am also going after a elk this fall. Not having a whole pile of pins to deal with when things happen fast could be a plus. Take a 50 yard shot with a slow bow. If what ever you are shooting at starts to take a step bad stuff is going to happen. The quicker the arrow gets there the less chance of that happening. To each their own. I am just trying to learn what is better. So far there is no clear cut evidence one way or another if speed is matched with weight. I don't want to shoot a elephant, just a elk. I don't want to lob arrows either. Trying to find a happy medium. To quiet a fast bow what is needed? In most cases a heavier arrow will cure that. I don't have the fastest bow but at 282 I am thinking I am fine with my setup after all the reading today. Might just go with a 25 grain heavier head. Never shot a elk with a bow yet and hopefully will get a chance this fall.
Tom
The fact is.....with lighter arrow you are more likely to hit your animal where you want....because it shoots flat......this is not opinion.
I shoot a 425gr arrow at 310fps and my bow is just as quiet as it was when I was shooting 495 grains at 290fps.......they might get loud at 330-350
I'm 1" low at 5 yards....1" high at 10 yards.....can't tell 15 and 20 apart at 2" high and dead on at 30.
So from 5-35 yards on an elk I can hold center of lungs and it's a kill shot.....
I have not had a turkey stop this yet either.
Happy medium......there is no need for 600gr arrows on anything around here............not that they don't work......I just think your better off with a arrow around 400-450 and 290-310 fps...these setups allow for 5-8 yard yardage estimation mistakes without the likelihood of wounding or missing.......and they kill just as good as a 600 grain arrow at 250fps....this of course, is just opinion.
MT, what kind of bow are you shooting? I want one!
I have never seen a bow that would shoot an arrow that heavy at that speed.
Must be 32" draw length at 85 lb draw weight and 5.5" brace height. :-)
A light arrow might give a 5 to 8 yard misjudge range while a 600 grain might be 4 to 7 or 3 to 5 but the heavier arrow might give you confidence to take a hard angle shot. I experience the hard angle scenerio a lot more than the misjudge distance scenerio. Everything is a tradeoff. If one uses a rangefinder lighter is not an advantage. One thing I have experienced is the lighter arrows and medium wt arrows shot exactly the same out if some high performance bows..exactly the same trajectory. Chronograph want show this..only trajectory test will.
Take MTcountryboy's advice.
Momentum has no DIRECT connection to penetration. Additional arrow mass will help get more KE from the bow and help retain the KE over distance (by reducing the velocity which reduces the drag).
Because KE and momentum share the same components, momentum will increase as arrow mass increases and is therefore mistakenly given the credit. However, it has nothing to do with penetration. KE is what propels the arrow and is what stops the arrow. KE and the average resisting force are what determine penetration.
If momentum was truly a factor in penetration, it wouldn't matter whether the momentum came from velocity or mass. Look at your combinations above that produce equal momentum: 740 gr @ 161 fps (should be 174fps) = 49.7 KE and 350 gr @ 367 fps = 104.7 KE
Do you really think that an arrow with 50 KE will have the same penetration as one with 105 KE ? Try it.
Turkey bow master your a real wealth of information. where do you come up with your "stats" and your thought process. The faster the flatter you shoot, the slower the more arch. The more pins you need the more your exact range is important. I shoot 316 FPS and I shot 8 deer with schwacker broadheads this year. EVERY one passed through period. The 9th deer was an operator error and I hit him in back as the string caught my arm. Still broke his right rear hip, and shattered the top of his leg and he went 40 yds. Its funny that my arrows penetrate further into any targer from 40 yds than they did with heavier arrows, in every target I shoot. Why is that I wonder after always reading about KE and momentum. The best part is one pin out to 40 yds really makes you confident. Tom, do what makes YOU the most confident, and dont let anyone else make you second guess what that is. The number one thing is to get your arrow to the target where you aimed. If that happens, you should have no problems.
That's exactly what I thought and it proved true for years. But recently the arrows have become so light and the bows so efficient that is is less true now than it was. A trajectory test shows this but it must be properly done.
bowtech cpxl 31.5 draw 65lbs (but my gauge does read up to 67 sometimes....I don't think it's very accurate....so it could be 67.....the limbs are backed out about 1/4")
run it through a calculator.....it should be faster.....but through 3 different crono's it varies between 307-312.....I just call it 310.
not sure if the winners choice slowed it down or if it just doesn't do what it supposed to.....I'm happy with it....it's around 90 ke....not that I care much about that.....it shoots pretty good (under 1" per 10 yards which is all I ask from a hunting bow)
It shoots right through quartered elk.......I don't think you need anywhere near this much weight or energy to kill an elk.
I know you don't need speed....guy's were killing elk with plaid shirts and bows that couldn't dream of 200 fps for years......but I'll take the speed if I can have it for free.
If shot placement is the most important (not offering opinion here) it's hard to argue that speed doesn't kill......speed just helps with shot placement......don't really care how far it goes after it leaves the animal.
MT your bow is a bad mamba jamba. My buddy had one. It can shoot up to 340 FPS if a person wants to go crazy with it.
Can anyone answer why my arrow penetrates further than my friends 50gr heavier arrow does inside of 40 yards but then his does better as we pass that 40 yard threshold?
Is it just a difference in where we are hitting the target because as we back up the shots are more erratic.
sundowner
the bow you mentioned would send my arrow around 375fps......if it didn't break at the launch....maybe faster.....
I can get you a pretty good deal on one if you want.
good buddy of mine shoots 430 grains (injections) at 302 ish with a insanity cpx with a 29.5 draw and 66 lbs
another one shoots a 440 grain axis at 303 ish out of an rpm 360 with a 30" draw and 66 lbs.
it's not hard to do......but you have to have the bow to do it.
I'm no fan boy by any means.....but the mathews and hoyt were slower.....really nice bows, but no nicer than the bowtech and the bowtech was faster......hence.....if the speed is free.....why not?
hammer
heavier arrows maintain energy better at longer distances......ballistic coefficient......your buddies arrow has a higher sectional density (assuming they are the same diameter)......meaning that it comes out of the bow slower.....but maintains it's speed better.....it will hit harder at longer distances than yours.
a bullet with a bc of .5 (ballistic coefficient) weighing 130 grains will produce roughly 2600 ft-lb enery at 3000 fps.......at 500 yards it will have about 1300 ft-lb energy
the same gun with a 150 grain bullet and a bc of .6 (more arrow dynamic but heavier) will leave the gun with about the same energy at 2800 fps.....but at 500 yard will have almost 1600 ft-lb's of energy.
the 130 grain bullet will hit about 6" higher......it's flatter....so more likely to hit where it is supposed too (elevation wise....not windage wise)......and there aren't too many animals that are going to care which one they get hit with.......dead is dead.
the laws of physics are not arguable (at least not by anyone I know) and they apply to all of us.......regardless of opinion.
I bet your arrow hits higher than his (this is assuming your bows are equal...draw..weight...ibo.....or any combo that produces the same ke out of the bow)
To make it simple for everyone shooting 60lbs and up, shoot a fmj correctly spined for your bow, and your good to hunt any big game on our continent!