OK Tech heads, on Chronographing.
#1
OK Tech heads, on Chronographing.
First off I'll say this as many newbies or those looking to learn might pick up a bit of advice.
My Allegiance is a 70 lb bow. Recently I chrono'd it an noticed it was slower than it once was and I know why. The cables/string has creeped. I checked ATA and sure enough plus I put it on the bow scale and it's down 4 lbs. Instead of a 70 lb bow it's maxed out at 66 lbs. I'm about ready to make a set of new cables and a string but want my 82nd to arrive first. I may just twist up the cables to get the 4lbs back and put the bow back into spec.
So while Brian (BPBowhunter) was up today for me to install his Gibblet string and cable, we played around with all my bows and his shooting and chrono'ing.
My bow, now at 66 lbs chronos in at 298-300 fps. Thing is, when Brian shot it, he was hitting 304-305 fps.
Riddle me this, why would he get 4-7 fps faster than I would shooting the same exact bow? The only difference between us is he is a 30" draw and I'm a 28.5" draw and the bow is set at 28.5"s.
My Allegiance is a 70 lb bow. Recently I chrono'd it an noticed it was slower than it once was and I know why. The cables/string has creeped. I checked ATA and sure enough plus I put it on the bow scale and it's down 4 lbs. Instead of a 70 lb bow it's maxed out at 66 lbs. I'm about ready to make a set of new cables and a string but want my 82nd to arrive first. I may just twist up the cables to get the 4lbs back and put the bow back into spec.
So while Brian (BPBowhunter) was up today for me to install his Gibblet string and cable, we played around with all my bows and his shooting and chrono'ing.
My bow, now at 66 lbs chronos in at 298-300 fps. Thing is, when Brian shot it, he was hitting 304-305 fps.
Riddle me this, why would he get 4-7 fps faster than I would shooting the same exact bow? The only difference between us is he is a 30" draw and I'm a 28.5" draw and the bow is set at 28.5"s.
#2
Giant Nontypical
Join Date: Feb 2003
Posts: 9,175
RE: OK Tech heads, on Chronographing.
I think he might be because he has to bend his elbow a little more than you do, and when he releases his arm probably snaps forward a little, giving the arrow a bit of extra boost. This is using the exact same principle of an old, old trick to getting a little more 'cast' from a longbow. Just a thought... aka wild guess.
#5
RE: OK Tech heads, on Chronographing.
ORIGINAL: Elkcrazy8
I would bet with a longer DL, he is pulling harder into the wall.
I would bet with a longer DL, he is pulling harder into the wall.
AP could be on to something but we could not explain it either. I could test that by leaning back into the shoot and bending my elbow more. Has merit but not sure it's that but of course I cannot say, I don't know what the cause is, thus the question. [8D]
#6
RE: OK Tech heads, on Chronographing.
I would bet with a longer DL, he is pulling harder into the wall.
Again Rob, just want to say thanks for all the help today, I really appreciated it.
Brian
#7
RE: OK Tech heads, on Chronographing.
No offense taken. However you cannot measure the amount of force each of you was pulling. It would seem to me that you would be able to get much more force from drawing short than you would trying to overdraw!!!! Even with each of you drawing as hard as you can off the wall. Just a thought.
#8
RE: OK Tech heads, on Chronographing.
Most likely, when he was shooting through the chrono, he was passing though the .....ah, I don't know what they're called....arms?? of the chrono, creating a different speed. Maybe he was a tad higher or lower, going through straighter....Something to that effect....
As you know, all those things will cause differnt readings.
As you know, all those things will cause differnt readings.
#9
RE: OK Tech heads, on Chronographing.
He is shooting through the chrony at a different angle and/or higher/lower in the chrony.
I can get 4 fps difference when shooting through on a different level.Try shooting through high and then shooting through low to see what you get.
What mobo was reffering to.
I can get 4 fps difference when shooting through on a different level.Try shooting through high and then shooting through low to see what you get.
What mobo was reffering to.