Anyone know if the "field test" for speed is close to an accurate assessment to give you a ballpark figure?
Stickem has some really nice tools there, just wondering how accurate some of those assessments can be. I don't have all the tools to be able to measure everything exactly, but if something like this is close that would be able to leave me with an idea of what the bows are doing.
Well, the auto calculator is pretty close if I put in my true draw length and not my AMO draw... I'll have to shoot some groups at 20 and 40 to see how close the field test chart is. I'll try and do that tonight or tomorrow.
Yeah I don't know how much I would trust that. I shot with my Bengal and with my Alien tonight
Bengal (65# peak measured at the factory - bottomed out): 11.25" drop
Alien (70# turned out 1.5 turns): 8.25" drop
While I don't know exactly what the bows are shooting, if I punch numbers into the calculator with a guess at weight on the string, I get around 290/300 respectively for the 2 bows. According to the field test 300fps would be about a 15.5" drop and 290 would be somewhere in between the 15.5 and 17.7"
I'm not obsessed with the speed, just curious to know for my own education.
Ihave used these calculators several times since the year 2000, when I shot for Pearson. Back then I did the shoot 20 & 40 chart.The one day I was havin a very good day of shooting(sub2" groups at 40)were about 16" lower than those at 20 yards. Using the chart that would calculate to about 294-295. The bow in question chrono'd 264 on three different chronographs.
This leads me to believe one of two things. Either the calculators are designed to make us feel good (ego thing) or the bows IBO ratings are greatly inflated. I'm inclined to think it's a bit of both.
I just need to put it up with the real technology and test it on a chrono. Gander Mtn near me has/had one ... heard someone shot it recently so I highly doubt it is still operational after that. A buddy had one but he moved to MI before I could check it out. I might revisit the thread on AT where the guy did a DIY coil chrono and built some software for it and tested it against his shop chrono.
Forgot to mention, I should have avoided doing this in the first place. There is a reason I don't shoot groups anymore if at all possible. Blew up an arrow. Had one come down right on another and break it off towards the tip of the shaft in the target.
This is the word that explains it.
BENGAL NUFF SAID!!!!!!
I ran the #'s of a couple of my bow/arrow combo's and did the field test thing with a couple and the stickem sites calculations were all high.
I have a chrono so I know what they really shoot.
I had the Martin Dealer Chrono my 2011 exile, after he set it up. It came in at 285 fps. I tried the calculator listed in this post, that came in at 274 fps. I think that the calculator will get you in the ball park, but my guess is that once you factor all of the info into it...it still is a ballpark. Nothing is going to beat a true chrono.
They are a useful tool though if you don't have a chrono handy. The online calculators should get you close enough for hunting purposes, at close range . The farther out you get, they less they will be usefull in the info.
On my current setup I chrono 250 and this calculator gives me 253. I use my OT2 "adjusted" IBO number.
I find with any of these calculators, with a particular bow, if I weight and check the actual specs I can adjust the IBO so the speed agrees with my chrono. Once done I use this adjusted IBO if I change DW, DL, Arrow weight, the calculator is pretty close to the actual chrono data.
I use both OT2 and AA with great satisfaction. If folks blindly input manufacturers IBO it's a crap shoot if the calculators work or not. As they say, garbage in, garbage out... There is a good chance the error is the IBO nuber, not the calculator.
I could care less about speed but I use this same method with DW, and arrow weight, looking at other calculations on unfamiliar set ups.
with a chrono i got 292 with this calculator i get 299. i like this calculator lol