With all the talk lately about how far, what can be killed, ethical shots and so on, I thought that I would put forth some thought from some very experienced shooters. Some of these might have been posted here before, if so, then it is about time it is brought back to the forum for more talk.
The artical below was from Horizontal Bowhunter Magazine a few years ago. A very good magazine with many good articals.
http://www.horizontalbowhunter.com/news/news.asp?ID=22
It is a very good artical explaining string jump and the distance for your shots. Here is another link that was sent to me by my nephew. It is basically a video which shows or explains how a deer can move before the arrow gets there at the longer distances. IT also shows how you can shoot with only one pin site (compound, but same princable) .
http://www.bowhunting.net/bowtube/media/85/The_Killing_Arc_-_Larry_Wise/
Remember that the shooting of the bow is not the only sound that is made. The arrow traveling through the air is actually more loud then the bow being shot. Even if you are able to make the bow 100% quiet, there will still be enough noise to alert deer, even if you can't hear it. So make your choice, speed of arrow or a little more quiet and how far to shoot. If I was you .......... choose what you are the most comfortable with.
STRING JUMP SOLUTIONS
In the course of any days business I invariably have at least one phone call from a customer concerned with string jump. Generally this issue is raised in the form of "How do I quiet my crossbow?" When the real concern should be "How do I stop deer from moving during the interval that my arrow is in flight?"
The realities of how a crossbow arrow is accelerated makes it impossible for a bow to be quiet enough that a deer can’t hear the release. This is especially true in areas where hunting pressure has made the deer jumpy, where I hunt a deer will panic if a mosquito passes wind! So what’s the answer to this problem? In my experience it comes down to common sense.
First we must reduce the time the arrow is in flight, which can be accomplished by either increased velocity or reduced distance, or a combination thereof.
Next, never shoot at a deer when it is looking towards you as light travels faster than sound and it can react more quickly.
Finally, remember that the more wired up a deer is, the faster it’ll react, and reduce your range accordingly. Of these rules the last two are pretty well self explanatory. The rocket science here lies in rule number one, so lets look at how velocity affects a deer’s ability to beat your arrow.
When I started crossbow hunting 30 years ago, the fastest crossbows shot about 250 FPS, and up until 10 years ago, this was the velocity I hunted at. Recent innovations have radically improved velocity, so I now hunt deer with an Exomag shooting a little over 325 FPS. Let’s compare how these two velocities affect a deer’s ability to string jump.
In order to compare we need to know the speed of sound, which I’ll round off to 1150 FPS, the arrows velocity, and (here’s the wild card), the deer’s reaction time.
Reaction time is the period where the sound is transmitted to the deer’s brain and translated into an actual action.
This could range from as little as .1 seconds if a deer is alarmed, to forever if it just doesn’t care. For this exercise I’m going to use .15 seconds, simply because it seems like a good place to start! The chart below represents actual flight times out to 50 yards in 10-yard increments. I will assume a 10% reduction in velocity at the 50 yard mark.
10 YD 20 YD 30 YD 40 YD 50 YD
250 FPS .12 .25 .37 .50
.63 Seconds
325 FPS .09 .19 .29 .39 .48 Seconds
Now, lets factor out the speed of sound @ 1150 FPS. The next table has the time it takes for the sound to arrive subtracted from the flight time.
10 YD 20 YD 30 YD 40 YD 50 YD
250 FPS .09 .20 .29 .40 .50 Seconds
325 FPS .06 .14 .21 .29 .35 Seconds
Sound Time .026 .052 .078 .104 .130 Seconds
Ok, we now know the periods of time that a deer can react if he isn’t actually watching you shoot. Now let’s subtract the deer’s supposed reaction time @ .15 seconds.
10 YD 20 YD 30 YD 40 YD 50 YD
250 FPS -.06 .05 .14 .25 .35
325 FPS -.09 -.01 .06 .14 .20
I know that this is all hypothetical, but I’d bet that the numbers here are darned close. The conclusion here is that my old Wolverine crossbow gave the deer zero opportunity to string jump out till about 15 yards, but my new Exomag gets me 21 yards.
Now even I am not foolish enough to assign a period of grace during which the deer’s vital area stays put, but we can certainly compare velocities. If that period was .1 seconds, I honestly wasn’t good for more than about 25 yards with the Wolverine before a wired up whitetail could get rolling, but my Exomag gets me out to 35 yards no problem. These are very vital yards.
I’m very sure from my personal experience that these figures are close as I used to always try to shoot a maximum of 25 yards with my old crossbow, but today I’ll shoot out past 30 yards without any concern for string jump.
I’m not saying "Don’t try to quiet your crossbow". Quiet is good, as long as you don’t sacrifice velocity to obtain it. The bottom line here, in my humble opinion, is simply know the range where string jump is an issue for your bows velocity, use the fastest arrow that your crossbow can comfortably and safely handle, and apply common sense in liberal doses. Just that easy.
I hope you’ve all had a safe and successful hunting season and I look forward to next issues column when we’ll get a bit technical about broadheads. Till then shoot straight and good hunting...Bill Troubridge