Can this be right?
02-28-2007, 07:39 PM
#1
Thread Starter
Join Date: Mar 2005
Location: Colorado
Posts: 4,127
Can this be right?
I was looking at the computer program that calculates arrow fps - plugged in my IBO, arrow weight, draw length, and pull weight. It gave me 279 fps. The bow is set at 49 lbs and will go up to 60 lbs. Just for fun, I plugged in the 60 lb. draw weight to see how much gain would it would show - expecting at least 25 fps. Program shows less than 10 fps gain. Double checked it with the same results. Are these programs even close?? Thanks. Roskoe
02-28-2007, 10:38 PM
#6
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: Can this be right?
10 fps is not right with 11# increase in draw weight.It would be closer to 20-25 fps.
My program gave me a 23 fps increase from 58#'s to 69#'s.I just used my setup.It was already set at 58#'s.
My program gave me a 23 fps increase from 58#'s to 69#'s.I just used my setup.It was already set at 58#'s.
03-01-2007, 02:23 PM
#7
Thread Starter
Join Date: Mar 2005
Location: Colorado
Posts: 4,127
RE: Can this be right?
I tried plugging in some really low pull weights (like 30#) with the same IBO, draw length, and arrow weight. Still was getting well over 200 fps. This can't be. If the wind lets up a little here this afternoon, I'm going to shoot this setup over my chronograph. I'm betting it's somewhere around 260 fps.
03-01-2007, 07:24 PM
#8
Thread Starter
Join Date: Mar 2005
Location: Colorado
Posts: 4,127
RE: Can this be right?
Now I'm really scratching my head. I shot two arrows over the chronograph about six feet from the bow. One registered 207 fps and the other 206. The bow, on a certified scale, is at 47 lbs. It is a 50/60 that has been backed off. This doesn't sound right either . . . . .
03-02-2007, 10:29 AM
#10
Thread Starter
Join Date: Mar 2005
Location: Colorado
Posts: 4,127
RE: Can this be right?
The bow is a Fred Bear Element. IBO is 302. They make two models: a 60/70 and a 50/60. It is the 50/60 and is turned down to 47 lbs. Arrows are the new Easton ST Excel carbon with 100 grain points. Arrows weigh right at 350 grains complete. Whisker biscuit rest. String peep. No string silencers.